Supplement Simplified Chinese translation of Project Page & Repository Page

Supplement zh_CN translation of Project Page & Repository Page to I18N

Progression

• Template (.pot file)
• Translation (.po file)
• Packaging (app.js file)

Links / references

• #32951 (closed) : Community translations (Meta)
• #33239 (closed) : Original Project Page & Repository Page translation
• Zanata project : Translation branch on the Zanata project