Embed relevent YT videos to docs (#1325)

* embed relevent YT videos to docs

* add title params

* modify youtube container styling

assets/scss/_grpc.scss

@@ -445,3 +445,16 @@ c - Component (Aware of its content/context...)
     display: none;
   }
 }
+
+.youtube-video {
+  position: relative;
+  width: 100%; 
+  padding-bottom: 46%; 
+}
+
+.youtube-video iframe {
+  position: absolute;
+  width: 80%; 
+  height: 100%; 
+  border: 0; 
+}

content/en/docs/guides/custom-load-balancing.md

@@ -16,6 +16,8 @@ A gRPC load balancing policy is given a list of server IP addresses by the name
 resolver. The policy is responsible for maintaining connections (subchannels)
 to the servers and picking a connection to use when an RPC is sent.
 
+{{< youtube id="7LYvl-nr0t8" class="youtube-video" title="gRPC Weighted Round Robin LB Policy" >}}
+
 ### Implementing Your Own Policy
 
 By default the `pick_first` policy will be used. This policy actually does no

content/en/docs/guides/opentelemetry-metrics.md

@@ -10,6 +10,8 @@ gRPC provides support for an OpenTelemetry plugin that provides metrics that can
 * Iterate on improving system performance
 * Setup continuous monitoring and alerting.
 
+{{< youtube id="L6FAtc8N8Vk" class="youtube-video" title="OpenTelemetry - The future of Observability" >}}
+
 ## Background
 
 OpenTelemetry is an observability framework to create and manage telemetry data. gRPC previously provided observability support through OpenCensus which has been [sunsetted](https://opentelemetry.io/blog/2023/sunsetting-opencensus/) in the favor of OpenTelemetry.

content/en/docs/platforms/web/_index.md

@@ -1,3 +1,5 @@
 ---
 title: Web
 ---
+
+{{< youtube id="l-W15x-Ked8" class="youtube-video" title="gRPC on Web" >}}

content/en/docs/what-is-grpc/_index.md

@@ -3,3 +3,5 @@ title: What is gRPC?
 description: New to gRPC? Start with the following pages
 weight: 1
 ---
+
+{{< youtube id="E3ez34fdC0k" class="youtube-video" title="Overview of gRPC" >}}

content/en/docs/what-is-grpc/core-concepts.md

@@ -10,6 +10,8 @@ Not familiar with gRPC? First read [Introduction to gRPC](../introduction/). For
 language-specific details, see the quick start, tutorial, and reference
 documentation for your language of choice.
 
+{{< youtube id="njC24ts24Pg" class="youtube-video" title="gRPC in 5 minutes" >}}
+
 ### Overview
 
 #### Service definition

content/en/docs/what-is-grpc/introduction.md

@@ -32,6 +32,8 @@ create a gRPC server in Java with clients in Go, Python, or Ruby. In addition,
 the latest Google APIs will have gRPC versions of their interfaces, letting you
 easily build Google functionality into your applications.
 
+{{< youtube id="cSGBbwvW1y4" class="youtube-video" title="getting started with gRPC" >}}
+
 ### Working with Protocol Buffers
 
 By default, gRPC uses [Protocol Buffers][], Google’s