fix: take the last possible occurence of token (#81)
fix: take the last possible occurence of token (#81)

When we match trigger char in the text ":" for example, we should return
the last possible occurence. Let's have a text "text:smile:good_smile" it this situation we should
return ":good_smile" not ":smile:good_smile"

CLOSE #61 #62
webscopeio/react-textarea-autocomplete,webscopeio/react-textarea-autocomplete,webscopeio/react-textarea-autocomplete