Reuse parts of README.md in docs/index.md

We want to also include some basic information of the project in the
documentation home page (but not all of it), so we use the include
extension to reuse some README sections.

Signed-off-by: Leandro Lucarella <luca-frequenz@llucax.com>

README.md

@@ -6,6 +6,8 @@
 
 ## Introduction
 
+<!-- introduction -->
+
 Frequenz Channels is a *channels* implementation for Python.
 
 According to [Wikipedia](https://en.wikipedia.org/wiki/Channel_(programming)):
@@ -20,14 +22,20 @@ Frequenz Channels are mostly designed after [Go
 channels](https://tour.golang.org/concurrency/2) but it also borrows ideas from
 [Rust channels](https://doc.rust-lang.org/book/ch16-02-message-passing.html).
 
+<!-- /introduction -->
+
 ## Supported Platforms
 
+<!-- supported-platforms -->
+
 The following platforms are officially supported (tested):
 
 - **Python:** 3.11
 - **Operating System:** Ubuntu Linux 20.04
 - **Architectures:** amd64, arm64
 
+<!-- /supported-platforms -->
+
 ## Quick Start
 
 We assume you are on a system with Python available. If that is not the case,

docs/index.md

@@ -2,19 +2,19 @@
 
 ## Introduction
 
-Frequenz Channels is a *channels* implementation for Python.
+{%
+   include-markdown "../README.md"
+   start="<!-- introduction -->"
+   end="<!-- /introduction -->"
+%}
 
-According to [Wikipedia](https://en.wikipedia.org/wiki/Channel_(programming)):
+## Supported Platforms
 
-> A channel is a model for interprocess communication and synchronization via
-> message passing. A message may be sent over a channel, and another process or
-> thread is able to receive messages sent over a channel it has a reference to,
-> as a stream. Different implementations of channels may be buffered or not,
-> and either synchronous or asynchronous.
-
-Frequenz Channels are mostly designed after [Go
-channels](https://tour.golang.org/concurrency/2) but it also borrows ideas from
-[Rust channels](https://doc.rust-lang.org/book/ch16-02-message-passing.html).
+{%
+   include-markdown "../README.md"
+   start="<!-- supported-platforms -->"
+   end="<!-- /supported-platforms -->"
+%}
 
 ## Installation
 
@@ -77,5 +77,5 @@ $ python3
 Python 3.11.4 (main, Jun  7 2023, 10:13:09) [GCC 12.2.0] on linux
 Type "help", "copyright", "credits" or "license" for more information.
 >>> import frequenz.channels
->>> 
+>>>
 ```

mkdocs.yml

@@ -133,3 +133,4 @@ plugins:
 watch:
   - "src"
   - CONTRIBUTING.md
+  - README.md