add doc policy (AtsushiSakai#609)

AtsushiSakai · web-flow · commit 88671e4ba100 · 2021-12-26T10:55:21.000+09:00
diff --git a/docs/how_to_contribute_main.rst b/docs/how_to_contribute_main.rst
@@ -65,6 +65,10 @@ Please check other documents for details.
 
 You can build the doc locally based on `doc README`_.
 
+Note that the `reStructuredText`_ based doc should only focus on the mathematics and the algorithm of the example.
+
+Documentations related codes should be in the python script as the header comments of the script or docstrings of each function.
+
 
 .. _`submit a pull request`:
 
