treewide: begin restructuring the module tree

modules/plugins/languages/markdown/config.nix

@@ -0,0 +1,40 @@
+{
+  pkgs,
+  config,
+  lib,
+  ...
+}: let
+  inherit (lib.nvim.lua) expToLua;
+  inherit (lib.modules) mkIf mkMerge;
+  inherit (lib.lists) isList;
+
+  cfg = config.vim.languages.markdown;
+  servers = {
+    marksman = {
+      package = pkgs.marksman;
+      lspConfig = ''
+        lspconfig.marksman.setup{
+          capabilities = capabilities;
+          on_attach = default_on_attach;
+          cmd = ${
+          if isList cfg.lsp.package
+          then expToLua cfg.lsp.package
+          else ''{"${cfg.lsp.package}/bin/marksman", "server"}''
+        },
+        }
+      '';
+    };
+  };
+in {
+  config = mkIf cfg.enable (mkMerge [
+    (mkIf cfg.treesitter.enable {
+      vim.treesitter.enable = true;
+      vim.treesitter.grammars = [cfg.treesitter.mdPackage cfg.treesitter.mdInlinePackage];
+    })
+
+    (mkIf cfg.lsp.enable {
+      vim.lsp.lspconfig.enable = true;
+      vim.lsp.lspconfig.sources.markdown-lsp = servers.${cfg.lsp.server}.lspConfig;
+    })
+  ]);
+}

modules/plugins/languages/markdown/default.nix

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

modules/plugins/languages/markdown/markdown.nix

@@ -0,0 +1,63 @@
+{
+  config,
+  pkgs,
+  lib,
+  ...
+}: let
+  inherit (builtins) attrNames;
+  inherit (lib.options) mkEnableOption mkOption;
+  inherit (lib.lists) isList;
+  inherit (lib.types) bool enum either package listOf str;
+  inherit (lib.nvim.lua) expToLua;
+  inherit (lib.nvim.types) mkGrammarOption;
+
+  cfg = config.vim.languages.markdown;
+  defaultServer = "marksman";
+  servers = {
+    marksman = {
+      package = pkgs.marksman;
+      lspConfig = ''
+        lspconfig.marksman.setup{
+          capabilities = capabilities;
+          on_attach = default_on_attach;
+          cmd = ${
+          if isList cfg.lsp.package
+          then expToLua cfg.lsp.package
+          else ''{"${cfg.lsp.package}/bin/marksman", "server"}''
+        },
+        }
+      '';
+    };
+  };
+in {
+  options.vim.languages.markdown = {
+    enable = mkEnableOption "Markdown markup language support";
+
+    treesitter = {
+      enable = mkOption {
+        description = "Enable Markdown treesitter";
+        type = bool;
+        default = config.vim.languages.enableTreesitter;
+      };
+      mdPackage = mkGrammarOption pkgs "markdown";
+      mdInlinePackage = mkGrammarOption pkgs "markdown-inline";
+    };
+
+    lsp = {
+      enable = mkEnableOption "Enable Markdown LSP support" // {default = config.vim.languages.enableLSP;};
+
+      server = mkOption {
+        description = "Markdown LSP server to use";
+        type = enum (attrNames servers);
+        default = defaultServer;
+      };
+
+      package = mkOption {
+        description = "Markdown LSP server package, or the command to run as a list of strings";
+        example = ''[lib.getExe pkgs.jdt-language-server " - data " " ~/.cache/jdtls/workspace "]'';
+        type = either package (listOf str);
+        default = servers.${cfg.lsp.server}.package;
+      };
+    };
+  };
+}