Documentation: Update docs for enum type

[mkly]

Enum type brackets need to be quoted or escaped in most shells.

• Update documenation and add an addition FAQ item about issue

[mkly]

Unfortunately, I failed to account for the shell with the use of brackets. Someone was having difficulty because of that, and I imagine they will not be the only one.

#704 (comment)

I've added some additional clarification to the documentation, but please let me know if you have any other ideas to help alleviate the confusion here. Thank you.

[sushantdhiman]

Thanks @mkly