Use bare tokens: PAT_FOR_GITHUB replaces CREDENTIALS_FOR_GITHUB

The sync workflow reads secrets.PAT_FOR_GITHUB as clear text and
parse_github_token and parse_gitea_token only check that the value is not
empty. No secret is JSON any more; the wiki publisher follows. Update the
tests, the guides, the README, PP-001 UC candidate 2 and the wiki pages with
their Danish and Bahasa Malaysia translations.

Task: MIL-002#5

wiki/Capabilities.md

@@ -43,7 +43,7 @@ activate Workflow
 Workflow -> Workflow: Read and validate secrets
 note right
 TOKEN_FOR_GITEA
-CREDENTIALS_FOR_GITHUB
+PAT_FOR_GITHUB
 end note
 
 alt secret validation failed