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.