Exclude underscores from auto formatting

[hexaflexahexagon]

Might need review to determine if we want this change.

Certain characters automatically add a trailing version after the cursor when typing it to complete formatting (e.g. *, _, <). this works fine for most characters but due to our game's unique usage of underscores this can make typing map names annoying as you never actually want the second character, resulting in the below screenshot happening very often.

It would be more convenient if underscores were somehow excluded from this behavior, though that would possibly frustrate users trying to italicize their text?