Add python project into the project page (#4752)

* Add python project into the project page

* Update README.md
Co-authored-by: 吴晟 Wu Sheng <wu.sheng@foxmail.com>

README.md

@@ -35,7 +35,7 @@ The core features are following.
 SkyWalking supports to collect telemetry (traces and metrics) data from multiple sources
 and multiple formats,
 including
-1. Java, [.NET Core](https://github.com/SkyAPM/SkyAPM-dotnet), [NodeJS](https://github.com/SkyAPM/SkyAPM-nodejs) and [PHP](https://github.com/SkyAPM/SkyAPM-php-sdk) auto-instrument agents.
+1. Java, [.NET Core](https://github.com/SkyAPM/SkyAPM-dotnet), [NodeJS](https://github.com/SkyAPM/SkyAPM-nodejs), [PHP](https://github.com/SkyAPM/SkyAPM-php-sdk) and [Python](https://github.com/apache/skywalking-python) auto-instrument agents.
 1. [Go agent](https://github.com/tetratelabs/go2sky).
 1. [LUA agent](https://github.com/apache/skywalking-nginx-lua), especially for Nginx, OpenResty.
 1. Service Mesh Observability. Support Mixer telemetry. Recommend to use Envoy Access Log Service (ALS) for better performance, first introduced at [KubeCon 2019](https://www.youtube.com/watch?v=tERm39ju9ew).
@@ -45,7 +45,7 @@ including
 # Document
 [8.x dev](docs/README.md) | [7.0](https://github.com/apache/skywalking/blob/v7.0.0/docs/README.md) | [6.6](https://github.com/apache/skywalking/blob/v6.6.0/docs/README.md), [6.5](https://github.com/apache/skywalking/blob/v6.5.0/docs/README.md).
 
-NOTICE, SkyWalking 8.0+ uses [v3 protocols](docs/en/protocols/README.md). They are incompatible with previous released. 
+NOTICE, SkyWalking 8.0+ uses [v3 protocols](docs/en/protocols/README.md). They are incompatible with previous released.
 
 # Downloads
 Please head to the [releases page](http://skywalking.apache.org/downloads/) to download a release of Apache SkyWalking.

docs/en/setup/README.md

 # Setup
-The document explains how to install Skywalking based on the kind of probes you are going to use. 
+The document explains how to install Skywalking based on the kind of probes you are going to use.
 If you don't understand, please read [Concepts and Designs](../concepts-and-designs/README.md) first.
 
 
@@ -16,11 +16,13 @@ If you have any issues, please check that your issue is not already described in
 
 - [LUA agent](https://github.com/apache/skywalking-nginx-lua). Introduce how to install the lua agent in Nginx + LUA module or OpenResty.
 
+- [Python Agent](https://github.com/apache/skywalking-python). Introduce how to install the Python Agent in a Python service.
+
 The following agents and SDKs are compatible with the SkyWalking's data formats and network protocols, but are maintained by 3rd-parties.
 You can go to their project repositories for additional info about guides and releases.
 
 - [SkyAPM .NET Core agent](https://github.com/SkyAPM/SkyAPM-dotnet). See .NET Core agent project document for more details.
-  
+
 - [SkyAPM Node.js agent](https://github.com/SkyAPM/SkyAPM-nodejs). See Node.js server side agent project document for more details.
 
 - [SkyAPM PHP SDK](https://github.com/SkyAPM/SkyAPM-php-sdk). See PHP agent project document for more details.