Improve documentation

- Use AsciiDoc instead of Markdown
- Adapt documentation check to AsciiDoc format
- Improve layout of syntax rules
- Add cross references between syntax rules

Ref. #703

doc/Development.md

@@ -2,7 +2,7 @@
 
 ## Installation
 
-The required dependencies are listed in the [README](../README.md#installation). After cloning the repository, `pip` can be used to install the project in editable mode. The use of a [virtual environment](https://docs.python.org/3/tutorial/venv.html) is recommended.
+The required dependencies are listed in the [README](../README.adoc#installation). After cloning the repository, `pip` can be used to install the project in editable mode. The use of a [virtual environment](https://docs.python.org/3/tutorial/venv.html) is recommended.
 
 ```Console
 $ virtualenv -p python3 venv
@@ -28,6 +28,6 @@ We accept pull requests [via GitHub](https://github.com/Componolit/RecordFlux/co
 
 When submitting a pull request, your topic branch should be rebased to the current upstream `main` branch. Verify that all automatic checks performed by `make check`, `make test` and `make prove` succeed before submitting the PR. For Python code we follow and automatically enforce the coding style of [Black](https://pypi.org/project/black/). You can format your code automatically using the `make format` target on the command line. For Ada code (examples as well as generated code) please follow [our Ada style guide](https://github.com/Componolit/ada-style).
 
-We enforce 100% branch coverage for Python code using [pytest](https://pytest.org). Make sure to add relevant test cases to achieve that for your code. See [the test documentation](/tests/README.md) and have a look at the existing test cases in the `tests` directory to get an idea of the structure of our test suite. Our Python code is also statically type-checked using [mypy](http://mypy-lang.org/). Make sure to include the required type annotations with your code.
+We enforce 100% branch coverage for Python code using [pytest](https://pytest.org). Make sure to add relevant test cases to achieve that for your code. See [the test documentation](/tests/README.adoc) and have a look at the existing test cases in the `tests` directory to get an idea of the structure of our test suite. Our Python code is also statically type-checked using [mypy](http://mypy-lang.org/). Make sure to include the required type annotations with your code.
 
 Your code will be reviewed by at least one core developer before inclusion into the project. Don't be discouraged should we have many comments and ask you for a lot of changes to your pull request. This even happens to the most experienced developers in our project and we consider these discussions an essential part of the development process and a necessity to maintain high quality. Don't hesitate to open an issue if you have any question or submit the pull request in draft mode first.