Fix tsconfig lib
Fix tsconfig lib

It's now more precise about what modern ES features we want in PS.

Zarel/Pokemon-Showdown,Mystifi/Exiled,xfix/Pokemon-Showdown,panpawn/Gold-Server,xfix/Pokemon-Showdown,DesoGit/Tsunami_PS,ShowdownHelper/Saffron,Lord-Haji/SpacialGaze,AustinXII/Pokemon-Showdown,xCrystal/Pokemon-Showdown,HoeenCoder/SpacialGaze,QuiteQuiet/Pokemon-Showdown,HoeenCoder/SpacialGaze,PS-Spectral/Spectral,aakashrajput/Pokemon-Showdown,Lord-Haji/SpacialGaze,svivian/Pokemon-Showdown,Zarel/Pokemon-Showdown,Sora-League/Sora,jumbowhales/Pokemon-Showdown,Mystifi/Exiled,sirDonovan/Pokemon-Showdown,ShowdownHelper/Saffron,QuiteQuiet/Pokemon-Showdown,AWailOfATail/Pokemon-Showdown,CreaturePhil/Showdown-Boilerplate,sirDonovan/Pokemon-Showdown,jumbowhales/Pokemon-Showdown,danpantry/Pokemon-Showdown,panpawn/Gold-Server,svivian/Pokemon-Showdown,sirDonovan/Pokemon-Showdown,panpawn/Pokemon-Showdown,panpawn/Gold-Server,aakashrajput/Pokemon-Showdown,HoeenCoder/SpacialGaze,Enigami/Pokemon-Showdown,xfix/Pokemon-Showdown,Sora-League/Sora,AustinXII/Pokemon-Showdown,Enigami/Pokemon-Showdown,AWailOfATail/Pokemon-Showdown,svivian/Pokemon-Showdown,xfix/Pokemon-Showdown,Zarel/Pokemon-Showdown,CreaturePhil/Showdown-Boilerplate,AWailOfATail/Pokemon-Showdown,DesoGit/Tsunami_PS,xCrystal/Pokemon-Showdown,aakashrajput/Pokemon-Showdown,svivian/Pokemon-Showdown,Mystifi/Exiled,xCrystal/Pokemon-Showdown,AustinXII/Pokemon-Showdown,HoeenCoder/SpacialGaze,CreaturePhil/Showdown-Boilerplate,panpawn/Pokemon-Showdown,Sora-League/Sora,Enigami/Pokemon-Showdown,QuiteQuiet/Pokemon-Showdown,DesoGit/Tsunami_PS,Enigami/Pokemon-Showdown,danpantry/Pokemon-Showdown,urkerab/Pokemon-Showdown,PS-Spectral/Spectral,urkerab/Pokemon-Showdown,urkerab/Pokemon-Showdown,svivian/Pokemon-Showdown,xfix/Pokemon-Showdown,Lord-Haji/SpacialGaze,PS-Spectral/Spectral,ShowdownHelper/Saffron,jumbowhales/Pokemon-Showdown