feat(doom): Enable language modules and disable stylix

This commit expands the Doom Emacs configuration by enabling a
wide array of programming language modules and tools. It also
decouples Emacs from the system's Stylix theming for more granular
control.

*** Modules
- Enabled language support for C/C++, Clojure, Go, Haskell,
  Python, Rust, Web, and Zig.
- Also enabled the ~company~, ~ibuffer~, ~upload~, and
  ~graphviz~ modules.
*** UI
- Switched to relative line numbers.
- Enabled icons for the ~vertico~ completion UI.
*** Nix
- Disabled the ~stylix~ target for Emacs to prevent it from
  overwriting the Doom theme.
- Added ~imagemagick~ as a dependency.

home/david/modules/programs/doom/default.nix

@@ -14,12 +14,13 @@ in
     };
   };
   config = lib.mkIf cfg.enable {
+    stylix.targets.emacs.enable = false;
     services.emacs.enable = true;
     programs.doom-emacs = {
       enable = true;
       emacs = pkgs.emacs-pgtk;
       extraPackages =
-        emacsPackages: with emacsPackages; [
+        ep: with ep; [
           melpaPackages.telega
         ];
       extraBinPackages = with pkgs; [
@@ -28,8 +29,10 @@ in
         git
         ripgrep
         fd
+        imagemagick
       ];
       doomDir = ./config;
+      provideEmacs = true;
     };
   };
 }