Add two more pages to documentation
What does the merge request do?
Found two more pages to add to the documentation, https://wiki.inkscape.org/wiki/INX_extension_descriptor_format and https://gitlab.com/inkscape/extensions/-/wikis/Extensions-Manager-Instructions.
In the project wiki we now only have https://gitlab.com/inkscape/extensions/-/wikis/inkex left, but that should be auto-generated (if at all?)
Summary for release notes
More documentation
Checklist
-
Add unit tests (if applicable) -
Changes to inkex/
are well documented -
Clean merge request history