Please provide multi-line support

[hehe-2016]

This plugin is very useful. I use it to convert camelCase to snake_case.
I hope you provide multi-line support, convert multi-line to multi-line, for instance:

sortField
sortType

convert to

sort_field
sort_type

another request is support consecutive uppercase letters to lowercase, only add underline before first uppercase letter.

customerBGCode -> customer_bgcode

[CheyenneForbes]

Just ran into the same issue too

[DiegoGary]

A workaround is using the multi-line editing in sublime and then converting the case.