New Twixt Commentator feature: Private Notes

Now you can take notes on your Twixt games right in Twixt Commentator. The "Add private note" link should be visible to the right on games in progress.

Private notes have pretty much all the same functionality of comments: moves are automatically clickable, you can preview them, edit them, and delete them.

Private notes are saved to local storage, so they don't go to the Twixt Commentator server at all, it's fast, and you don't need to be logged in, or even have an account.

I should mention, though, some limitations of the local storage approach: you need to be on the same browser on the same computer to see your notes. Notes can get deleted if you clear browsing data. Notes can also get deleted for other reasons; for example, in Safari, if you haven't visited Commentator in 7 days, Safari deletes your old notes. Local storage is generally limited to 5-10MB depending on your browser, which should be more than plenty for this purpose, but if you have other sites that aggressively use local storage, you may see old notes disappear. I think most of these cases should not be a problem, but it would be interesting to know if you run into an issue.

Of course, if you have any issues or comments, let me know.

Actual defects should be logged to the Github site,
https://github.com/ahensel/twixt-commentator/issues