Fix outlook render bug in newsletters
This MR tries to fix render issues with old IE and Outlook versions that have been reported several times (ugh)
- add explicit px-based width for graphs
- replace svg by png
- Doing this for the Newsletter Oct 2022 and Dec 2022.
- June 2022 NL was formatted in the old version anyway
- Future newsletter (April 2023) will need corresponding adaptation !691 (merged)
Edited by Uwe Jandt (DESY, HIFIS)