plugins/completion: move to by-name

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

plugins/completion/cmp/sources/cmp-tabby.nix

@@ -1,69 +0,0 @@
-{
-  lib,
-  helpers,
-  config,
-  ...
-}:
-with lib;
-let
-  cfg = config.plugins.cmp-tabby;
-in
-{
-  meta.maintainers = [ maintainers.GaetanLepage ];
-
-  # TODO: introduced 24-06-18, remove after 24.11
-  imports =
-    let
-      basePluginPath = [
-        "plugins"
-        "cmp-tabby"
-      ];
-      settingsPath = basePluginPath ++ [ "settings" ];
-    in
-    [
-      (mkRenamedOptionModule (basePluginPath ++ [ "extraOptions" ]) settingsPath)
-      (mkRenamedOptionModule (basePluginPath ++ [ "host" ]) (settingsPath ++ [ "host" ]))
-      (mkRenamedOptionModule (basePluginPath ++ [ "maxLines" ]) (settingsPath ++ [ "max_lines" ]))
-      (mkRenamedOptionModule (basePluginPath ++ [ "runOnEveryKeyStroke" ]) (
-        settingsPath ++ [ "run_on_every_keystroke" ]
-      ))
-      (mkRenamedOptionModule (basePluginPath ++ [ "stop" ]) (settingsPath ++ [ "stop" ]))
-    ];
-
-  options.plugins.cmp-tabby = {
-    settings = helpers.mkSettingsOption {
-      description = "Options provided to the `require('cmp_ai.config'):setup` function.";
-
-      options = {
-        host = helpers.defaultNullOpts.mkStr "http://localhost:5000" ''
-          The address of the tabby host server.
-        '';
-
-        max_lines = helpers.defaultNullOpts.mkUnsignedInt 100 ''
-          The max number of lines to complete.
-        '';
-
-        run_on_every_keystroke = helpers.defaultNullOpts.mkBool true ''
-          Whether to run the completion on every keystroke.
-        '';
-
-        stop = helpers.defaultNullOpts.mkListOf types.str [ "\n" ] ''
-          Stop character.
-        '';
-      };
-
-      example = {
-        host = "http://localhost:5000";
-        max_lines = 100;
-        run_on_every_keystroke = true;
-        stop = [ "\n" ];
-      };
-    };
-  };
-
-  config = mkIf cfg.enable {
-    extraConfigLua = ''
-      require('cmp_tabby.config'):setup(${helpers.toLuaObject cfg.settings})
-    '';
-  };
-}