treewide: begin restructuring the module tree

modules/plugins/utility/preview/markdown-preview/config.nix

@@ -0,0 +1,28 @@
+{
+  pkgs,
+  config,
+  lib,
+  ...
+}: let
+  inherit (lib.strings) optionalString stringLength concatMapStringsSep;
+  inherit (lib.modules) mkIf;
+  inherit (lib.nvim.vim) mkVimBool;
+  inherit (lib.nvim.dag) entryAnywhere;
+
+  cfg = config.vim.utility.preview.markdownPreview;
+in {
+  config = mkIf cfg.enable {
+    vim.startPlugins = [pkgs.vimPlugins.markdown-preview-nvim];
+
+    vim.configRC.markdown-preview = entryAnywhere ''
+      let g:mkdp_auto_start = ${mkVimBool cfg.autoStart}
+      let g:mkdp_auto_close = ${mkVimBool cfg.autoClose}
+      let g:mkdp_refresh_slow = ${mkVimBool cfg.lazyRefresh}
+      let g:mkdp_filetypes = [${concatMapStringsSep ", " (x: "'" + x + "'") cfg.filetypes}]
+      let g:mkdp_command_for_global = ${mkVimBool cfg.alwaysAllowPreview}
+      let g:mkdp_open_to_the_world = ${mkVimBool cfg.broadcastServer}
+      ${optionalString (stringLength cfg.customIP > 0) "let g:mkdp_open_ip = '${cfg.customIP}'"}
+      ${optionalString (stringLength cfg.customPort > 0) "let g:mkdp_port = '${cfg.customPort}'"}
+    '';
+  };
+}

modules/plugins/utility/preview/markdown-preview/default.nix

@@ -0,0 +1,6 @@
+{
+  imports = [
+    ./markdown-preview.nix
+    ./config.nix
+  ];
+}

modules/plugins/utility/preview/markdown-preview/markdown-preview.nix

@@ -0,0 +1,58 @@
+{lib, ...}: let
+  inherit (lib.options) mkEnableOption mkOption;
+  inherit (lib.types) bool str listOf;
+in {
+  options.vim.utility.preview = {
+    markdownPreview = {
+      enable = mkEnableOption "Markdown preview in neovim with markdown-preview.nvim";
+
+      autoStart = mkOption {
+        type = bool;
+        default = false;
+        description = "Automatically open the preview window after entering a Markdown buffer";
+      };
+
+      autoClose = mkOption {
+        type = bool;
+        default = true;
+        description = "Automatically close the preview window after leaving a Markdown buffer";
+      };
+
+      lazyRefresh = mkOption {
+        type = bool;
+        default = false;
+        description = "Only update preview when saving or leaving insert mode";
+      };
+
+      filetypes = mkOption {
+        type = listOf str;
+        default = ["markdown"];
+        description = "Allowed filetypes";
+      };
+
+      alwaysAllowPreview = mkOption {
+        type = bool;
+        default = false;
+        description = "Allow preview on all filetypes";
+      };
+
+      broadcastServer = mkOption {
+        type = bool;
+        default = false;
+        description = "Allow for outside and network wide connections";
+      };
+
+      customIP = mkOption {
+        type = str;
+        default = "";
+        description = "IP-address to use";
+      };
+
+      customPort = mkOption {
+        type = str;
+        default = "";
+        description = "Port to use";
+      };
+    };
+  };
+}