💥 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/editor/file-templates/templates/ruby-mode/__module

@@ -0,0 +1,12 @@
+# `(progn
+     (setq-local pkgs (split-string (string-remove-prefix (concat (doom-project-root) "lib/") (file-name-sans-extension buffer-file-name)) "/" t))
+     (setq-local pkgs-p (eq (length pkgs) 1))
+     (setq-local pkg-module (replace-regexp-in-string " " "::" (capitalize (if pkgs-p (car pkgs) (string-join (butlast pkgs) " "))) nil t))
+
+     (concat "lib/" (file-name-nondirectory buffer-file-name)))`
+
+module `pkg-module`
+`(when pkgs-p "  VERSION='0.0.1'\n\n")``(concat "  class " (if pkgs-p "<< self" (capitalize (car (last pkgs)))))`
+    `%`${0:# Code here}
+  end
+end