i18n: add zh_CN for test

[chisaato]

First step of #439

[TheDuckCow]

Great to already see this contribution in progress! Thank you for taking this first step, we will be eager to look over once this is review-ready.

[TheDuckCow]

Sorry it's taken this long for us to get back here, it's been a busy time. This is fantastic start! Uploading this video to call out a number of translations that would be great to add. Based on the video, keys that need to be added (made this list to make it faster to do translations and add to the dictionary). Let us know if you have an interest in making this change, otherwise I can attempt to google translate it, though likely won't be great

• Related to auto updater:
  • Update ready!
  • Ignore
  • Update
  • Open website
  • Install manually
• World Imports panel:
  • Open (as in "Open jmc2obj")
  • Swap Texture Pack
  • Cycles Only :C
  • Sync Materials
  • Find missing textures
  • Animate textures
• World tools panel:
  • Create MC Sky
  • Prep world
  • Render Panorama
• Skin swapper:
  • Add skin
  • Remove skin
  • Download username list
  • Reload skins
• Spawner:
  • All Mobs
  • Install new mob
  • Generate models from .json files
  • No models loaded
  • Reload assets
  • Install mob icon
  • Uninstall mob
  • Place model
  • Import model (.json)
  • Resource pack
  • Reload models
  • Item spawner
  • No items loaded
  • Generate items from textures`
  • Place item
  • Item from file
  • Reload items
  • Effects + weather
  • No effects loaded
  • Entity spawner
  • import pre-rigged entities
  • No entities loaded
  • Entity file
  • Meshswap spawner
  • Reload MeshSwap
• Preferences
  • World Importing & Meshswapping
  • Tutorials (and all the content in the tutorials page..)
  • Tracking/Updater (and all the content here...)
  • Default Exporter (we need to remove the : from the ui panel too)
  • jmc2obj executable
  • Mineways executable
  • World OBJ Exports Folder
  • Meshswap assets
  • Entity assets
  • Texture / Resource packs
  • Effects folder
  • Open effects folder
  • Verbose logging
  • Feature set (maybe needs : at end)

demo.translation.mp4

[TheDuckCow]

I'm approving this as-is since it's a net improvement with no downside, though not all keys have been created. Still, we could merge in the meantime to set the structure in place.