fix typo

Author: mario-holubar

plugin/bullets.vim

@@ -161,7 +161,7 @@ fun! s:parse_bullet_text(line_text)
   if s:bullet_cache isnot v:null
     let l:cached = get(s:bullet_cache, a:line_text, v:null)
     if l:cached isnot v:null
-      " Return a copy so as not to break the referene
+      " Return a copy so as not to break the reference
       return copy(l:cached)
     endif
   endif