Improve documentation for methods and their return types

[tiennou]

Brief Description

This copies over the return into from the official docs to have their meaning directly into the docs. Should be purely comment changes (except a few long lines prettier decided to reformat).

Checklists

• Test passed
• Coding style (indentation, etc)
• Edits have been made to src/ files not index.d.ts
• Run npm run compile to update index.d.ts

[tiennou]

Fixed the missing ERR_NOT_OWNER on RoomPosition.createConstructionSite() and the accidental deletion of PowerCreep.transfer 😅.

[tiennou]

Thanks for the fixups! 🎉