Readme updates (#1631)

* Readme updates

* typos

* keep main readme simple

* less verbose in getting started

* length

* Update docs/metrics/getting-started.md

Co-authored-by: Reiley Yang <reyang@microsoft.com>

* link fix

* link fix

Co-authored-by: Reiley Yang <reyang@microsoft.com>

README.md

@@ -21,8 +21,10 @@ Framework](https://dotnet.microsoft.com/download/dotnet-framework) except for
 
 ## Getting Started
 
-If you are new here, please see [get started in 5
+If you are new here, please see getting started docs for
-minutes](./docs/trace/getting-started/README.md).
+[logs](./docs/logs/getting-started/README.md),
+[metrics](./docs/metrics/getting-started.md), and
+[trace](./docs/trace/getting-started/README.md).
 
 This repository includes multiple installable components, available on
 [NuGet](https://www.nuget.org/profiles/OpenTelemetry). Each component has its

docs/metrics/getting-started.md

@@ -6,6 +6,9 @@ Metrics API and SDK is in alpha/experimental stage, and are not recommended for
 any production use. Both the API, and SDK implementation is subject to
 significant changes.
 
+Please check the [Metric support
+plan](https://github.com/open-telemetry/opentelemetry-dotnet/issues/1501).
+
 ## Sample usage
 
 Check

docs/trace/getting-started/README.md

@@ -56,3 +56,19 @@ An OpenTelemetry
 is configured to subscribe to the activities from the source
 `MyCompany.MyProduct.MyLibrary`, and export it to `ConsoleExporter`.
 `ConsoleExporter` simply displays it on the console.
+
+## OpenTelemetry .NET and relation with .NET Activity API
+
+If you tried the above program, you may have already noticed that the terms
+`ActivitySource` and `Activity` were used instead of `Tracer` and `Span` from
+OpenTelemetry specification. This results from the fact that, OpenTelemetry .NET
+is a somewhat unique implementation of the OpenTelemetry project, as parts of
+the tracing API are incorporated directly into the .NET runtime itself. From a
+high level, what this means is that the `Activity` and `ActivitySource` classes
+from .NET runtime represent the OpenTelemetry concepts of
+[Span](https://github.com/open-telemetry/opentelemetry-specification/blob/master/specification/trace/api.md#span)
+and
+[Tracer](https://github.com/open-telemetry/opentelemetry-specification/blob/master/specification/trace/api.md#tracer)
+respectively. Read
+[this](../../../src/OpenTelemetry.Api/README.md#introduction-to-opentelemetry-net-tracing-api)
+to learn more.

src/OpenTelemetry.Api/README.md

@@ -6,6 +6,7 @@
 * [Installation](#installation)
 * [Introduction](#introduction)
   * [Tracing API](#tracing-api)
+  * [Logging API](#logging-api)
   * [Metrics API](#metrics-api)
 * [Introduction to OpenTelemetry .NET Tracing
   API](#introduction-to-opentelemetry-net-tracing-api)
@@ -70,7 +71,7 @@ with the intent to produce continuous summaries of those measurements.
 
 _**Warning:** OpenTelemetry .NET has a prototype Metrics API implementation only
 and is not recommended for any production use. The API is expected to change
-heavily._
+heavily. Please check the [Metric support plan](https://github.com/open-telemetry/opentelemetry-dotnet/issues/1501)._
 
 ## Introduction to OpenTelemetry .NET Tracing API