Fix typos and spelling

[mrxz]

Description:
Let a spellchecker run on the code and fixed various typos and spelling mistakes.

I did briefly test integrating spellchecking in eslint, and while it works, the precommit hook becomes too slow and there are many false-positives (e.g. event names like xbuttonup). It might still be worthwhile to consider setting up some spellchecking tools/configuration along with an A-Frame specific wordlist.

Changes proposed:

• Fixed various typos and spelling mistakes

[dmarcos]

Thanks. Wouldn't add it as a hook maybe something optional that can be run manually.

[dmarcos]

Thanks