Update/complete the `Game modifier` articles

[TicClick]

trafficstars

• [ ] 10K: stub + see TODOs in the article
• [ ] Auto
• [ ] Autopilot
• [ ] Cinema
• [ ] Co-op
• [x] Double time: good enough
• [ ] Easy
• [ ] Fade In
• [ ] Fade Out: stub + see TODOs in the article
• [ ] Flashlight: stub + perhaps needs a small rewrite and cleanup
• [ ] Half Time
• [ ] Hard Rock
• [ ] Hidden
• [ ] Mirror
• [ ] Mod multiplier
• [ ] Nightcore
• [ ] No Fail
• [ ] No Video: stub + see TODO in the article
• [ ] Perfect
• [ ] Random
• [ ] Relax
• [ ] ScoreV2
• [ ] Spun Out: stub + needs a title fix
• [ ] Sudden Death
• [ ] Summary: need to decide if we still want it -- overlaps with the index page (/wiki/Gameplay/Game_modifier) so probably can be merged into that
• [ ] Target Practice
• [ ] xK