LeetCode Submit Extension 0.5.0

Chrome extension package for WineChord Books LeetCode submit.

Install:

1. Download leetcode-submit.zip.
2. Unzip it.
3. Open chrome://extensions, enable Developer mode, click
   Load unpacked, and select the unzipped folder.
4. Sign in to leetcode.cn in the same Chrome profile.

The page sends only the problem slug, language, and editor code to
the extension. LeetCode cookies stay inside Chrome extension APIs.