💥 Remove :feature category

:feature was a "catch-all" category. Many of its modules fit better in
other categories, so they've been moved:

- feature/debugger -> tools/debugger
- feature/evil -> editor/evil
- feature/eval -> tools/eval
- feature/lookup -> tools/lookup
- feature/snippets -> editor/snippets
- feature/file-templates -> editor/file-templates
- feature/workspaces -> ui/workspaces

More potential changes in the future:

- A new :term category for terminal emulation modules (eshell, term and
  vterm).
- A new :os category for modules dedicated to os-specific functionality.
  The :tools macos module would fit here, but so would modules for nixos
  and arch.
- A new :services category for web-service integration, like wakatime,
  twitter, elfeed, gist and pastebin services.

modules/lang/php/README.org

@@ -8,7 +8,7 @@ This module adds support for PHP 5.3+ (including PHP7).
 + Code refactoring commands (~php-refactor-mode~)
 + Unit-test commands (~phpunit~)
 + Support for ~laravel~ and ~composer~ projects (with project-specific snippets)
-+ [[../../feature/file-templates/templates/php-mode][File templates]]
++ [[../../editor/file-templates/templates/php-mode][File templates]]
 + [[https://github.com/hlissner/emacs-snippets/tree/master/php-mode][Snippets]]
 
 #+begin_quote