Fix `readme.rst`.
Tested locally by running `python setup.py doc`, no more errors from observability.
Only error is related to grpc_status:
```
WARNING: autodoc: failed to import module 'rpc_status' from module 'grpc_status'; the following exception was raised:
cannot import name 'status_pb2' from 'google.rpc' (unknown location)
```
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Closes#35988
PiperOrigin-RevId: 609820414
Actually build O11y artifacts.
### Testing
* Manually installed the `.whl` and verified it's working locally (For Python 3.8 + Linux).
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Closes#35578
PiperOrigin-RevId: 600566829
### Description
Fix https://github.com/grpc/grpc/issues/24470.
Adding one example which demonstrate the following use cases:
* Generate RPC ID on client side and propagate to server.
* Context propagation from client to server.
* Context propagation between different server interceptors and the
server handler.
## Use:
1. Start server: `python3 -m async_greeter_server_with_interceptor`
2. Start client: `python3 -m async_greeter_client`
### Expected Logs:
* On client side:
```
Sending request with rpc id: 73bb98beff10c2dd7b9f2252a1e2039e
Greeter client received: Hello, you!
```
* On server side:
```
INFO:root:Starting server on [::]:50051
INFO:root:Interceptor1 called with rpc_id: default
INFO:root:Interceptor2 called with rpc_id: Interceptor1-default
INFO:root:Handle rpc with id Interceptor2-Interceptor1-73bb98beff10c2dd7b9f2252a1e2039e in server handler.
```
cc @markdroth
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The newly updated [gRPC Python](https://grpc.io/docs/languages/python/) page, contains links to the quick start, tutorial, examples and more! Link directly to that page, rather than refer to only part of its contents.
* Expose the C-Core API in Cython layer
* Handle the object translation
* Create a separate package for Channelz specifically
* Handle nullptr and raise exception if seen one
* Translate C++ Channelz unit tests
* Adding 5 more invalid query unit tests
Adding peripheral utility for grpcio-channelz package
* Add to `pylint_code.sh`
* Add to Python build script
* Add to artifact build script
* Add to Bazel
* Add to Sphinx module list
* Use templates instead of generating them every time
* Theme changed
* Add grpc_* modules
* APIs grouped
* No documentation for class members without docstring
* Add docstring for status code