docs/glossary: add warning explaining that the content is work in progress
Glossary
########
+.. Warning::
+ This is work-in-progress, since the utilities and wrappers developed in F4PGA are being redesigned (from shell to Python).
+ Therefore, the terms and definitions shown below are subject to change.
+ It is strongly suggested not to rely on the content below until this note is updated/removed.
+
.. glossary::
:sorted:
