Stop rerendering mathjax on every keypress

Bug Report

Description

When editing messages Mathjax is rerendered on every keypress.

Behavior

Expected: Mathjax should be rerendered on every edit, potentially with a 1-2 seconds timeout.

Actual: Navigation with arrows also triggers a rerender.

Steps to Reproduce

1. Start editing a message with a live preview
2. Add e.g. x=0 to the message.
3. Press an arrow key
4. Observe that mathjax is rerendering

Additional Information

This is a low impact issue