Migration from OSDN

[magicant]

We've been suffering from an availability problem with the OSDN site for the past few months, and it's pretty uncertain that the site will return to normal since it was acquired by OSCHINA. So I'm moving this project to GitHub.

Previously, GitHub was only considered a mirror, but now it is the main host of this project.

• [x] Update README 76ac86ebb16a7ad4ab83018ccc2f93b62fff5b30
• [x] Host the website on gh-pages 54cb7825b6dd02f730ec85fadc2e549ce155d2f6
• [x] Host the manpage on gh-pages ef89c08e26ab2f31baa51731d5e7bfe065dd431c 9f79c75980b311312e8e6af0a08785af32dcfd2d
• [x] Redirect https://yash.osdn.jp to gh-pages (if possible)
• [x] Update the manpage 082d62f43d9d8adc4569504f376314218c867613
• [x] Update the website contents 5a7e119351d0c8789854158567ec9f3584ed64e9
• [x] Migrate wiki pages
  • [ ] Committing
  • [ ] FrontPage
  • [x] HowToTranslate → TRANSLATING.md
  • [ ] JapaneseEnglishTranslation (Obsolete)
  • [x] Release → RELEASING.md
  • [ ] Yashrc/Intro (Obsolete)
  • [ ] Yashrc/Prompt (Obsolete)
• [x] Update the Jenkins configuration for the existing jobs
• [x] Automate more tests on Jenkins and update RELEASING.md
• [x] Migrate OSDN tickets to GitHub issues (if possible)
• [x] Update any remaining references to OSDN in the code repository a108297171b14527a99dcf310533fef4b235cd0b
• [x] Update the OSDN project description to redirect visitors to GitHub