Changes to the ct.js' API to reflect in docs

[CosmoMyzrailGorynych]

• ct. is not needed to be written. Properties that dropped the ct. prefix without major changes: meta|camera|templates|rooms|actions|inputs|content|backgrounds|styles|res|emitters|tilemaps|timer|u|pixiApp|stage|loop|fittoscreen|assert|capture|cutscene|desktop|eqs|filters|flow|fs|gamedistribution|inherit|gamepad|keyboard|mouse|pointer|nakama|noise|nanoid|place|random|sprite|storage|touch|transition|ulid|vgui|vkeys|yarn
• ct.sound is now sounds, ct.sound.spawn is now sounds.play
• ct.delta is now u.delta, ct.deltaUi is u.deltaUi
• ct.room is rooms.current
• ct.pixiApp is pixiApp
• fittoscreen is now a hidden built-in API. Controlled through these ⬇
• A wild settings appears:
  • highDensity is a toggleable boolean (retina mode);
  • targetFps configures target FPS and its cap;
  • viewMode is old fittoscreen's mode with one of these values (can be changed during runtime): 'asIs' | 'fastScale' | 'fastScaleInteger' | 'expand' | | 'scaleFit' | 'scaleFill'
• camera is not writable now.
  • What's the alternative?
    • Is it really needed?
• ct.roomWidth and ct.roomHeight are now rooms.current.viewWidth and rooms.current.viewHeight
• /*!%start%*/ injection was removed.
• Base classes appear. Panels and text labels can't have animation events, or animation properties.
• Skeleton support is removed.
• Docs for sounds API.

• Update tutorials to match the new IDE and API