Add git commit message template

[GreasySlug]

Although it is unlikely to be used, I have created a template file for git commit message

Changes proposed in this PR:

• add git commit message temple
• update dev guide about commit_message
  • EN
  • JA
  • zh_cn(not yet)
  • zh_tw(not yet)

@mtshiba

[C-BJ]

Documents for zh_CN and zh_TW are less urgent

[GreasySlug]

Documents for zh_CN and zh_TW are less urgent

I'm in no hurry, so you can commit to this when you can

[mtshiba]

Thank you!