add English document
tiny fixes
Merge pull request #1 from rhysd/doc/en

英語ドキュメント
Update document.
Fix mapping name.
Merge branch 'master' of github.com:osyo-manga/vim-marching
Rename options.
Add buffer local options.
Fix bug.
Fix wait time.
Add README/
About the place of English document
Follow c34a8e00ee
Fix refs
Tiny fix
Fix caching.
Improve caching.
Improve complete word.
Fix complete "dup".
Add sync complete.
Fix typo.