[TASK] Add documentation
[!!][API] Remove Text field type, rename UnStored to Text

Since Entities are retrieved after querying by their ids, there is no need to
store additional data into the index. So the Text field type has no usage
in this context, and should be replaced with UnStored. But for backwards
compatibility and convenience, rename UnStored as Text, and remove
old Text.
[FIX] Change displayed version
[TASK] Update composer.json version