plugins/completion: move to by-name

- Move nvim-cmp to plugins/cmp
- Move other completion plugins to plugins/by-name

plugins/cmp/sources/cmp-ai.nix

@@ -0,0 +1,95 @@
+{
+  lib,
+  helpers,
+  config,
+  ...
+}:
+with lib;
+let
+  cfg = config.plugins.cmp-ai;
+in
+{
+  meta.maintainers = [ maintainers.GaetanLepage ];
+
+  options.plugins.cmp-ai = {
+    settings = helpers.mkSettingsOption {
+      description = "Options provided to the `require('cmp_ai.config'):setup` function.";
+
+      options = {
+        max_lines = helpers.defaultNullOpts.mkUnsignedInt 50 ''
+          How many lines of buffer context to use.
+        '';
+
+        run_on_every_keystroke = helpers.defaultNullOpts.mkBool true ''
+          Generate new completion items on every keystroke.
+        '';
+
+        provider = helpers.defaultNullOpts.mkStr "HF" ''
+          Which AI provider to use.
+
+          Check the [README](https://github.com/tzachar/cmp-ai/blob/main/README.md) to learn about
+          available options.
+        '';
+
+        provider_options = helpers.defaultNullOpts.mkAttrsOf types.anything { } ''
+          Options to forward to the provider.
+        '';
+
+        notify = helpers.defaultNullOpts.mkBool true ''
+          As some completion sources can be quit slow, setting this to `true` will trigger a
+          notification when a completion starts and ends using `vim.notify`.
+        '';
+
+        notify_callback = helpers.defaultNullOpts.mkLuaFn' {
+          description = ''
+            The default notify function uses `vim.notify`, but an override can be configured.
+          '';
+          pluginDefault = ''
+            function(msg)
+              vim.notify(msg)
+            end
+          '';
+          example = ''
+            function(msg)
+              require('notify').notify(msg, vim.log.levels.INFO, {
+                title = 'OpenAI',
+                render = 'compact',
+              })
+            end
+          '';
+        };
+
+        ignored_file_types = helpers.defaultNullOpts.mkAttrsOf' {
+          type = types.bool;
+          description = "Which filetypes to ignore.";
+          pluginDefault = { };
+          example = {
+            lua = true;
+            html = true;
+          };
+        };
+      };
+
+      example = {
+        max_lines = 1000;
+        provider = "HF";
+        notify = true;
+        notify_callback = ''
+          function(msg)
+            vim.notify(msg)
+          end
+        '';
+        run_on_every_keystroke = true;
+        ignored_file_types = {
+          lua = true;
+        };
+      };
+    };
+  };
+
+  config = mkIf cfg.enable {
+    extraConfigLua = ''
+      require('cmp_ai.config'):setup(${helpers.toLuaObject cfg.settings})
+    '';
+  };
+}