refactor: Add mods/_index.scss to aggregate styles

Author: lindwurm

app/javascript/styles/application-akane-blue.scss

@@ -22,3 +22,5 @@
 @use 'mastodon/dashboard';
 @use 'mastodon/rtl';
 @use 'mastodon/rich_text';
+
+@use 'mods';

app/javascript/styles/application.scss

@@ -22,3 +22,5 @@
 @use 'mastodon/dashboard';
 @use 'mastodon/rtl';
 @use 'mastodon/rich_text';
+
+@use 'mods';

app/javascript/styles/mods/_index.scss

@@ -0,0 +1,7 @@
+@use 'announcements';
+@use 'bigger-publish';
+@use 'compact-padding';
+@use 'custom';
+@use 'legacy-style';
+@use 'reverse-nav';
+@use 'wider-column';