modules: start breaking down core modules; simplify tree structure

modules/plugins/notes/obsidian/obsidian.nix

@@ -0,0 +1,39 @@
+{
+  config,
+  lib,
+  ...
+}: let
+  inherit (lib) mkEnableOption mkOption types;
+in {
+  options.vim.notes = {
+    obsidian = {
+      enable = mkEnableOption "complementary neovim plugins for Obsidian editor";
+      dir = mkOption {
+        type = types.str;
+        default = "~/my-vault";
+        description = "Obsidian vault directory";
+      };
+
+      daily-notes = {
+        folder = mkOption {
+          type = types.str;
+          default = "";
+          description = "Directory in which daily notes should be created";
+        };
+        date-format = mkOption {
+          type = types.str;
+          default = "";
+          description = "Date format used for creating daily notes";
+        };
+      };
+
+      completion = {
+        nvim_cmp = mkOption {
+          # if using nvim-cmp, otherwise set to false
+          type = types.bool;
+          description = "If using nvim-cmp, otherwise set to false";
+        };
+      };
+    };
+  };
+}