improve exercise text

content/sharing.rst

@@ -248,4 +248,8 @@ Exercises
    If you want to try this out:
     - Take `this repository <https://github.com/bast/html2pdf>`_ as starting point and inspiration.
     - Don't focus too much on what this container does, but rather `how it is built <https://github.com/bast/html2pdf/tree/main/.github/workflows>`_.
-    - To build a new version, one needs to send a pull request which updates ``VERSION`` and modifies the definition file.
+    - To build a new version, one needs to send a pull request which updates
+      the file ``VERSION`` and modifies the definition file.
+    - Using this approach, try to build a very simple container definition
+      directly on GitHub where the goal is to have both the definition file
+      and the image file in the same place.