improve character highlighting
update document for highlighting improvement and tiny typo fixes
refactoring for fix-direction feature
fix 't' and 'T' behavior

standard 't' and 'T' mappings don't move cursor
when it is first move and cursor position matches the condition
update the highlight when direction changes in 't' and 'T'
do tiny refactorings
fix tiny miss fix
fix highlight attribute
Merge branch 'dev'