impr(command line): add 'ctrl p' and 'ctrl n' navigation key binds (@xaskii) (#5949)

### Description

Adds `<Ctrl-p>` and `<Ctrl-n>` binds to the command-line. These are from
Emacs, but you can navigate up and down menus all over macOS and its
apps with these keybinds.

#### Relevant PRs
Refactor that removed the binds:
https://github.com/monkeytypegame/monkeytype/pull/5180
adding "vim keybinds":
https://github.com/monkeytypegame/monkeytype/pull/4019

Confirmed working on macOS (safari, firefox, and chrome). On windows,
`<Ctrl-n>`: opening a new window takes priority, but that's expected
behaviour.

### Checks

- [ ] Adding quotes?
- [ ] Make sure to include translations for the quotes in the
description (or another comment) so we can verify their content.
- [ ] Adding a language or a theme?
- [ ] If is a language, did you edit `_list.json`, `_groups.json` and
add `languages.json`?
  - [ ] If is a theme, did you add the theme.css?
- Also please add a screenshot of the theme, it would be extra awesome
if you do so!
- [x] Check if any open issues are related to this PR; if so, be sure to
tag them below.
- [x] Make sure the PR title follows the Conventional Commits standard.
(https://www.conventionalcommits.org for more info)
- [x] Make sure to include your GitHub username prefixed with @ inside
parentheses at the end of the PR title.

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Closes issue discussed in discord.

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frontend/src/ts/commandline/commandline.ts

@@ -619,11 +619,19 @@ const modal = new AnimatedModal({
 
     input.addEventListener("keydown", async (e) => {
       mouseMode = false;
-      if (e.key === "ArrowUp" || (e.key.toLowerCase() === "k" && e.ctrlKey)) {
+      if (
+        e.key === "ArrowUp" ||
+        (e.ctrlKey &&
+          (e.key.toLowerCase() === "k" || e.key.toLowerCase() === "p"))
+      ) {
         e.preventDefault();
         await decrementActiveIndex();
       }
-      if (e.key === "ArrowDown" || (e.key.toLowerCase() === "j" && e.ctrlKey)) {
+      if (
+        e.key === "ArrowDown" ||
+        (e.ctrlKey &&
+          (e.key.toLowerCase() === "j" || e.key.toLowerCase() === "n"))
+      ) {
         e.preventDefault();
         await incrementActiveIndex();
       }