make category indexable
make subject indexable
Merge branch 'feature/indexable-category' into develop

* feature/indexable-category:
  make category indexable
Merge branch 'feature/indexable-subject' into develop

* feature/indexable-subject:
  make subject indexable
make forums entites indexable
Merge branch 'feature/indexable-forum-entities' into develop

* feature/indexable-forum-entities:
  make forums entites indexable
update type name of indexable entities