Boss bars, GUI improvements, additional placeholders and more!

New:

• New BossBarProgress config.yml option to temporarily display a boss bar showing progress when a player receives an achievement.

• Add placeholders for the total number of achievements in individual categories. All placeholder documentation has been migrated to the official PlaceholderAPI Wiki.

• The main GUI page now displays the number of achievements received by the player in each category in addition to the total number of achievements in the category.

• In lang.yml, list-achievements-in-category-singular and list-achievements-in-category-plural can be set to empty to remove lores from the main GUI page.

Translations:

• French translation update, thanks to @Nogapra for their contribution!
• Chinese translation update, thanks to @MagmaBlock for their contribution!

Other:

• The issue templates now follow the new GitHub forms format to make it easier for users to submit good quality support cases.
• Several external dependencies were updated to keep the plugin at the state of the art!