Update builtins.txt

[BlindWanderer]

Added missing functions and events.

I have not attempted to add missing constants.

[BlindWanderer]

It was a goal to make an article for every constant however...

1. When do you make articles for constants for functions that are pre-release/preview only? You don't want to be too proactive when documenting constants (especially when you don't know their values).
2. Some of the constants share an article. I can't confirm this right now but I believe TEXTURE_BLANK and TEXTURE_PLYWOOD share an article. For some constants it makes no sense to have two separate articles. There are maybe 4 or 5 of these articles (when it comes to the wiki templates, they are a poorly handled edge case).

I'll look into adding a (hidden?) section to the articles that contain just the signature. It's easy enough to add and we can put undocumented constants into it on the function/event articles. lslint won't be the only software that could benefit from this.