Cura layer display plugin

This is a post-processing plugin for Cura that adds M117 lines upon layer change so the printer displays which layer it is working on out of how many (tested with cura 3.4 and anet a6).

## Install

Copy LayerProgress.py in your local scripts folder (%appdata%/cura/3.4/scripts/) and (re)start cura.

## Use

Enable in the post-processing plugins panel.