Add emacs

modules/emacs/default.nix

@@ -0,0 +1,87 @@
+{ inputs, config, pkgs, ... }: let
+  newpkgs = pkgs.appendOverlays
+    (with inputs.emacs-overlay.overlays; [ emacs package ]);
+
+  tree-sitter-parsers = grammars: with grammars; [
+    tree-sitter-bash
+    tree-sitter-c
+    tree-sitter-c-sharp
+    tree-sitter-cmake
+    tree-sitter-cpp
+    tree-sitter-css
+    tree-sitter-dot
+    tree-sitter-elisp
+    tree-sitter-glsl
+    tree-sitter-html
+    tree-sitter-java
+    tree-sitter-javascript
+    tree-sitter-json
+    tree-sitter-json5
+    tree-sitter-kotlin
+    tree-sitter-latex
+    tree-sitter-llvm
+    tree-sitter-lua
+    tree-sitter-make
+    tree-sitter-markdown
+    tree-sitter-markdown-inline
+    tree-sitter-nickel
+    tree-sitter-nix
+    tree-sitter-prisma
+    tree-sitter-python
+    tree-sitter-regex
+    tree-sitter-rust
+    tree-sitter-scss
+    tree-sitter-sql
+    tree-sitter-toml
+    tree-sitter-tsx
+    tree-sitter-typescript
+    tree-sitter-vim
+    tree-sitter-yaml
+  ];
+
+  custom-emacs =
+    with newpkgs;
+    ((emacsPackagesFor emacs-unstable).emacsWithPackages (epkgs: with epkgs; [
+      avy
+      company
+      cmake-font-lock
+      direnv
+      editorconfig
+      evil
+      evil-collection
+      evil-goggles
+      face-explorer
+      flycheck
+      frames-only-mode
+      fussy
+      kotlin-mode
+      lsp-mode
+      lsp-treemacs
+      lsp-ui
+      magit
+      markdown-mode
+      nasm-mode
+      nix-mode reformatter # required by nix mode
+      projectile
+      rainbow-mode
+      string-inflection
+      (treesit-grammars.with-grammars (grammars: tree-sitter-parsers grammars))
+      treemacs
+      treemacs-evil
+      treemacs-projectile
+      treemacs-magit
+      use-package
+      vertico
+      which-key
+      ws-butler
+    ]));
+in {
+  home-manager.users.${config.main-user} = {
+    home.packages = [ custom-emacs ];
+
+    services.emacs = {
+      enable = true;
+      package = custom-emacs;
+    };
+  };
+}