Add tools/publish_wiki.py and the Publish wiki workflow, which make the
Gitea wiki equal wiki/ through the wiki REST API when a change to wiki/ is
merged to main. It needs its own secret TOKEN_FOR_GITEA_WIKI, refuses an
empty source and checks that the English pages are current first.
Document the secret in the credentials and troubleshooting guides and
regenerate the affected wiki pages.
Task: MIL-005#8
Add tools/build_wiki.py, which builds the five English wiki pages into
wiki/, rewrites links so they work inside the wiki and reports pages that
differ from their sources. Offline tests cover the conversion and assert
that the committed pages are current.
Task: MIL-005#3
Tirsvad