Merge gem annotations with gem RBIs to simplify user experience

[KaanOzkan]

We can merge the annotation RBIs with the gem RBI during tapioca gem command instead of relying on tapioca annotations.

I think not worrying about the annotations command can simplify the user experience. Also this will result in a single gem related RBI which conceptually is more consistent especially with the future plans of inline RBI versioning for the annotations.

[bitwise-aiden]

Update vault, discourse, and other places we encourage the use of annotation command.

[bitwise-aiden]

I'm going on Pat leave, this will be picked up when the project resumes.