Make ktem official (#134)

* Move kotaemon and ktem into same folder

* Update docs

* Update CI

* Resolve mypy, isorts

* Re-allow test pdf files

mkdocs.yml

@@ -59,7 +59,7 @@ plugins:
               - "!^_"
             members_order: source
             separate_signature: true
-          paths: [kotaemon]
+          paths: [libs/kotaemon]
   - git-revision-date-localized:
       enable_creation_date: true
       type: timeago