plugins/completion: move to by-name

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

plugins/by-name/coq-nvim/default.nix

@@ -0,0 +1,94 @@
+{
+  lib,
+  helpers,
+  pkgs,
+  ...
+}:
+with lib;
+helpers.neovim-plugin.mkNeovimPlugin {
+  name = "coq-nvim";
+  originalName = "coq_nvim";
+  package = "coq_nvim";
+
+  maintainers = [
+    maintainers.traxys
+    helpers.maintainers.Kareem-Medhat
+  ];
+
+  extraOptions = {
+    # TODO: should this enable option be replaced with `nullable = true` in the package option?
+    installArtifacts = mkEnableOption "and install coq-artifacts";
+    artifactsPackage = mkPackageOption pkgs "coq-artifacts" {
+      extraDescription = "Installed when `installArtifacts` is enabled.";
+      default = [
+        "vimPlugins"
+        "coq-artifacts"
+      ];
+    };
+  };
+
+  # TODO: Introduced 12-03-2022, remove 12-05-2022
+  optionsRenamedToSettings = [
+    "xdg"
+    "autoStart"
+  ];
+  imports =
+    let
+      basePath = [
+        "plugins"
+        "coq-nvim"
+      ];
+      settingsPath = basePath ++ [ "settings" ];
+    in
+    [
+      (mkRenamedOptionModule (basePath ++ [ "recommendedKeymaps" ]) (
+        settingsPath
+        ++ [
+          "keymap"
+          "recommended"
+        ]
+      ))
+
+      (mkRenamedOptionModule (basePath ++ [ "alwaysComplete" ]) (
+        settingsPath
+        ++ [
+          "completion"
+          "always"
+        ]
+      ))
+    ];
+
+  callSetup = false;
+  settingsOptions = {
+    auto_start = helpers.mkNullOrOption (
+      with helpers.nixvimTypes; maybeRaw (either bool (enum [ "shut-up" ]))
+    ) "Auto-start or shut up";
+
+    xdg = mkOption {
+      type = types.bool;
+      default = true;
+      description = "Use XDG paths. May be required when installing coq with Nix.";
+    };
+
+    keymap.recommended = helpers.defaultNullOpts.mkBool true "Use the recommended keymaps";
+
+    completion.always = helpers.defaultNullOpts.mkBool true "Always trigger completion on keystroke";
+  };
+
+  extraConfig = cfg: {
+    extraPlugins = mkIf cfg.installArtifacts [ cfg.artifactsPackage ];
+
+    globals = {
+      coq_settings = cfg.settings;
+    };
+
+    extraConfigLua = "require('coq')";
+
+    plugins.lsp = {
+      preConfig = ''
+        local coq = require 'coq'
+      '';
+      setupWrappers = [ (s: ''coq.lsp_ensure_capabilities(${s})'') ];
+    };
+  };
+}