Add Python version to documentation, poe command (#26)

* Command to serve documentation

* Warning for Python version

Author: AdrienVannson

docs/getting-started.md

@@ -12,6 +12,9 @@ It is possible to install `betterproto2_compiler` using pip:
 pip install betterproto2_compiler
 ```
 
+!!! warning
+    The compiler needs Python 3.10, 3.11 or 3.12. Don't worry! The generated code will be compatible with all Python versions from Python 3.8 to Python 3.13.
+
 ## Compile a proto file
 
 Create the following `example.proto` file.

pyproject.toml

@@ -99,6 +99,10 @@ help = "Check that the source code is formatted"
 cmd = "ruff check src tests"
 help = "Check the code with the Ruff linter"
 
+[tool.poe.tasks.serve-docs]
+cmd = "mkdocs serve"
+help = "Serve the documentation locally"
+
 [tool.poe.tasks.generate_lib]
 shell = """
 protoc \