a0.4.0 Release Candidate 6 Changelogs

Additions:
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Changes:
- Renamed "Download" buttons in the Worlds, Mods, and Resources tabs to "Export"
- Moved the "Community Worlds (Mod.io) text to the top instead of the bottom
- Changed the hotbar selector to be solid black instead of white with inversion, so it's more visible

Removals:
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Fixes:
- Fixed a bug where holding the pause key would cause the pause menu to disappear
- Fixed a bug where the resolution text in the Settings Video tab would disappear after clicking Reset Tab
- Fixed a bug where the game would automatically name world slots that didn't exist