New options for /aach list GUI

New:

• New HideProgressiveAchievements parameter in config.yml. This is in essence a mixture of the existing ObfuscateProgressiveAchievements and HideNotReceivedCategories parameters, it displays not received achievements as locked in the GUI. The lock item can be customised with the new AchievementLock parameter in gui.yml.
• New CategoryLock parameter in gui.yml, allowing to customise the lock item used when HideNotReceivedCategories is enabled.

Improvements:

• The support page now has issue templates to help users ask questions and report bugs more efficiently.