Username Rules
- Only contains alphanumeric characters, underscore and dot.
- Underscore and dot can't be at the end or
start of a username (e.g
_username/username_/.username/username.). - Underscore and dot can't be next to each other (e.g
user_.name). - Underscore or dot can't be used multiple times in a row (e.g
user__name/user..name). - Number of characters must be between 4 to 32.