taskchampion: update docs

- update CI branch filters so workflows actually run on merge
- update CI docs deployment target
- update links
- fix typos
- remove references to `ta` cli which was removed
- remove build-docs.sh script which duplicates publish-docs.yml workflow

.github/workflows/checks.yml

@@ -3,7 +3,7 @@ name: checks
 on:
   push:
     branches:
-      - main
+      - develop
   pull_request:
     types: [opened, reopened, synchronize]