Added .md extension where missing (#4171)

* Added .md extension where missing

* Fixing a few more links

docs/admin/collecting-logs/README.md

@@ -1,6 +1,9 @@
 # Logging
 
-You can use [Fluent Bit](https://docs.fluentbit.io/), a log processor and forwarder, to collect Kubernetes logs in a central directory. This is not required to run Knative, but can be helpful with [Knative Serving](../../serving), which automatically delete pods and associated logs when they are no longer needed.
+You can use [Fluent Bit](https://docs.fluentbit.io/), a log processor and forwarder, to collect
+Kubernetes logs in a central directory.
+This is not required to run Knative, but can be helpful with
+[Knative Serving](../../serving/README.md), which automatically deletes pods and associated logs when they are no longer needed.
 
 Fluent Bit supports exporting to a number of other log providers. If you already have an existing log provider, for example, Splunk, Datadog, ElasticSearch, or Stackdriver, you can follow the [FluentBit documentation](https://docs.fluentbit.io/manual/pipeline/outputs) to configure log forwarders.
 

docs/admin/collecting-metrics/eventing-metrics/metrics.md

@@ -36,7 +36,9 @@ By aggregating the metrics over the http code, events can be separated into two
 | event_dispatch_latencies | The time spent dispatching an event from a in-memory Channel | Histogram | container_name<br>event_type<br>namespace_name=<br>response_code<br>response_code_class<br>unique_name | Milliseconds | Stable
 
 !!! note
-    A number of metrics eg. controller, Go runtime and others are omitted here as they are common across most components. For more about these metrics check the [Serving metrics API section](../../serving-metrics/metrics).
+    A number of metrics eg. controller, Go runtime and others are omitted here as they are common
+    across most components. For more about these metrics check the
+    [Serving metrics API section](../serving-metrics/metrics.md).
 
 ## Eventing sources
 

docs/admin/eventing/broker-configuration.md

@@ -68,7 +68,8 @@ data:
 
 Now every Broker created in the cluster that does not have a `spec.config` will be configured to use the `kafka-channel` ConfigMap.
 
-For more information about creating a `kafka-channel` ConfigMap to use with your Broker, see the [Kafka Channel ConfigMap](../kafka-channel-configuration/#create-a-kafka-channel-configmap) documentation.
+For more information about creating a `kafka-channel` ConfigMap to use with your Broker, see the
+[Kafka Channel ConfigMap](kafka-channel-configuration.md#create-a-kafka-channel-configmap) documentation.
 
 ### Changing the default Channel implementation for a namespace
 

docs/admin/install/README.md

@@ -1,17 +1,17 @@
 # Installing Knative
 
 !!! tip
-    You can install a local distribution of Knative for development use by following the [Getting started guide](../../getting-started/){_blank}.
+    You can install a local distribution of Knative for development use by following the [Getting started guide](../../getting-started/README.md){_blank}.
 
 You can install the Serving component, Eventing component, or both on your cluster by using one of the following deployment options:
 
 - Using a YAML-based installation:
-    - [Install Knative Serving by using YAML](../install/serving/install-serving-with-yaml)
-    - [Install Knative Eventing by using YAML](../install/eventing/install-eventing-with-yaml)
-- Using the [Knative Operator](knative-with-operators).
-- Following the documentation for vendor managed [Knative offerings](../install/knative-offerings).
+    - [Install Knative Serving by using YAML](../install/serving/install-serving-with-yaml.md)
+    - [Install Knative Eventing by using YAML](../install/eventing/install-eventing-with-yaml.md)
+- Using the [Knative Operator](knative-with-operators.md).
+- Following the documentation for vendor managed [Knative offerings](../install/knative-offerings.md).
 
-You can also [upgrade an existing Knative installation](../upgrade/).
+You can also [upgrade an existing Knative installation](../upgrade/README.md).
 
 !!! note
     Knative installation instructions assume you are running Mac or Linux with a bash shell.

docs/admin/install/eventing/eventing-installation-files.md

@@ -5,7 +5,8 @@ This guide provides reference information about the core Knative Eventing YAML f
 - The custom resource definitions (CRDs) and core components required to install Knative Eventing.
 - Optional components that you can apply to customize your installation.
 
-For information about installing these files, see [Installing Knative Eventing using YAML files](../install-eventing-with-yaml).
+For information about installing these files, see
+[Installing Knative Eventing using YAML files](install-eventing-with-yaml.md).
 
 The following table describes the installation files included in Knative Eventing:
 

docs/admin/install/installing-istio.md

@@ -247,7 +247,7 @@ See the [Uninstall Istio](https://istio.io/docs/setup/install/istioctl/#uninstal
 
 ## What's next
 
-- Try the [Getting Started with App Deployment guide](../serving/getting-started-knative-app) for Knative serving.
+- Try the [Getting Started with App Deployment guide](../../serving/getting-started-knative-app.md) for Knative Serving.
 
 [1]:
   https://istio.io/docs/setup/kubernetes/additional-setup/sidecar-injection/#manual-sidecar-injection

docs/admin/install/operator/configuring-serving-cr.md

@@ -313,7 +313,7 @@ Update `spec.ingress.istio.knative-local-gateway` to select the labels of the ne
 
 ### Default local gateway name:
 
-Go through the guide [here](../installing-istio.md/#installing-istio-without-sidecar-injection) to use local cluster gateway,
+Go through the guide [here](../installing-istio.md#installing-istio-without-sidecar-injection) to use local cluster gateway,
 if you use the default gateway called `knative-local-gateway`.
 
 ### Non-default local gateway name:

docs/admin/install/serving/install-serving-with-yaml.md

@@ -220,7 +220,7 @@ The following tabs expand to show instructions for installing each Serving exten
     install the components needed to support the provisioning of TLS certificates
     through cert-manager.
 
-    1. Install [cert-manager version v1.0.0 or later](../../../../serving/installing-cert-manager).
+    1. Install [cert-manager version v1.0.0 or later](../../../serving/installing-cert-manager.md).
 
     1. Install the component that integrates Knative with `cert-manager` by running the command:
 
@@ -229,7 +229,7 @@ The following tabs expand to show instructions for installing each Serving exten
         ```
 
     1. Configure Knative to automatically configure TLS certificates by following the steps in
-    [Enabling automatic TLS certificate provisioning](../../../../serving/using-auto-tls).
+    [Enabling automatic TLS certificate provisioning](../../../serving/using-auto-tls.md).
 
 === "TLS with HTTP01"
 

docs/admin/install/serving/serving-installation-files.md

@@ -5,7 +5,7 @@ This guide provides reference information about the core Knative Serving YAML fi
 - The custom resource definitions (CRDs) and core components required to install Knative Serving.
 - Optional components that you can apply to customize your installation.
 
-For information about installing these files, see [Installing Knative Serving using YAML files](../install-serving-with-yaml).
+For information about installing these files, see [Installing Knative Serving using YAML files](install-serving-with-yaml.md).
 
 The following table describes the installation files included in Knative Serving:
 

docs/admin/serving/feature-flags.md

@@ -364,4 +364,4 @@ spec:
 * **Type**: Extension
 * **ConfigMap key:** `tag-header-based-routing`
 
-This flags controls whether [tag header based routing](samples/tag-header-based-routing/) is enabled.
+This flags controls whether [tag header based routing](../../serving/samples/tag-header-based-routing/README.md) is enabled.