Support for version 6?

[kyuilisworking]

Hi, was wondering if you'd update this for version 6, which seems to support touchscreens better and is generally more suited for iOS.

[NghiaTranUIT]

I've checked out and it seems that CodeMirror 6 is fully re-written, so I'm not sure if it's feasible to upgrade.

I will spend a couple of days doing it since we're working on the iOS Proxyman version, which needs a better version of CodeMirror 👍