feat(emacs): support typescript-mode in Eglot plugin

Teach our Emacs plugin to register the quick-lint-js LSP server in Eglot for
typescript-mode. This lets Eglot users enable quick-lint-js in .ts files.

Author: strager

docs/CHANGELOG.md

@@ -16,6 +16,7 @@ Semantic Versioning.
 * `typeof myVar === undefined` now reports [E0458][] ("typeof result is of type
   string and so will never equal undefined; use 'undefined' instead").
   (Implemented by [CoderMuffin][].) ([#1207][])
+* Emacs: The Eglot plugin now supports `typescript-mode`.
 
 ### Fixed
 

plugin/emacs/eglot-quicklintjs.el

@@ -18,6 +18,7 @@
 ;;   ;; Optional: Make Eglot run automatically when `js-mode' is loaded
 ;;   (eglot-ensure))
 ;; (add-hook 'js-mode-hook #'my-eglot-quicklintjs-setup)
+;; (add-hook 'typescript-mode-hook #'my-eglot-quicklintjs-setup)
 
 ;;; Code:
 
@@ -38,9 +39,10 @@
   :group 'eglot-quicklintjs
   :type '(repeat string))
 
-(add-to-list 'eglot-server-programs `(js-mode . (,eglot-quicklintjs-program
-                                                  "--lsp-server"
-                                                  ,@eglot-quicklintjs-args)))
+(add-to-list 'eglot-server-programs
+             `((js-mode typescript-mode) . (,eglot-quicklintjs-program
+                                            "--lsp-server"
+                                            ,@eglot-quicklintjs-args)))
 
 (provide 'eglot-quicklintjs)
 

website/public/install/emacs/configure/index.ejs.html

@@ -50,12 +50,6 @@ <h2 id="eglot">Eglot</h2>
         <code>eglot-quicklintjs</code> library:
       </p>
       <pre><code class="elisp">(require 'eglot-quicklintjs)</code></pre>
-      <p>
-        TODO:
-        <a href="https://github.com/quick-lint/quick-lint-js/issues/1146"
-          >TypeScript support</a
-        >
-      </p>
       <p>
         To speed up JavaScript linting, configure Eglot to send changes to
         quick-lint-js immediately without delay by adding the following to your
@@ -67,9 +61,11 @@ <h2 id="eglot">Eglot</h2>
   ;; checking buffer. The default is 0.5 (500ms)
   (setq-local eglot-send-changes-idle-time 0)
 
-  ;; Optional: Make Eglot run automatically when `js-mode' is loaded
+  ;; Optional: Make Eglot run automatically when `js-mode' or `typescript-mode'
+  ;; is loaded.
   (eglot-ensure))
-(add-hook 'js-mode-hook #'my-eglot-quicklintjs-setup)</code></pre>
+(add-hook 'js-mode-hook #'my-eglot-quicklintjs-setup)
+(add-hook 'typescript-mode-hook #'my-eglot-quicklintjs-setup)</code></pre>
 
       <h2 id="flycheck">Flycheck</h2>
       <p>