Update docsource/090_contribute.rst

Co-authored-by: Pedro M. Baeza <[email protected]>

docsource/090_contribute.rst

@@ -19,7 +19,7 @@ For example, if you want to propose the migration script of the ``account``
 module from version 15.0 to version 16.0:
 
   * Always ensure that there is no work already in progress by a community member.
-    For that purpose, go the issue named "Migration to version 16.0" on github
+    For that purpose, go the issue named "Migration to version NN.0" on GitHub, where NN is the version for which you want to propose the script.
     `here <https://github.com/OCA/OpenUpgrade/issues/3681/>`_.
 
     Sometimes, the pull request is not yet registered in the issue, so it's not bad to do a search on the opened pull requests with the name of the module to look for.