doc: Remove training sidebar

The-Compiler · The-Compiler · commit 89b6b2ee2b1c · 2021-05-26T14:15:58.000+02:00
(cherry picked from commit 54e4aad)
diff --git a/doc/en/index.rst b/doc/en/index.rst
@@ -1,10 +1,12 @@
 :orphan:
 
-.. sidebar:: Next Open Trainings
+..
+    (note: please leave this here, next open training to follow soon)
+    .. sidebar:: Next Open Trainings
 
-   - `Professionelles Testen für Python mit pytest <https://www.enterpy.de/lecture_compact1.php?id=12713>`_ (German), part of the enterPy conference, April 22nd (sold out) and May 20th, remote.
+       - `Professionelles Testen für Python mit pytest <https://www.enterpy.de/lecture_compact1.php?id=12713>`_ (German), part of the enterPy conference, April 22nd (sold out) and May 20th, remote.
 
-   Also see `previous talks and blogposts <talks.html>`_.
+       Also see `previous talks and blogposts <talks.html>`_.
 
 .. _features:
 
