Add a badge for the Emacs package.

CONTRIBUTING.md

@@ -81,8 +81,14 @@ through the code after the breakpoint.
 Install the `live-py-mode` package as described in the README file, then replace all the files in
 `~/.emacs.d/elpa/live-py-mode-X.Y` with symbolic links to your git repository.
 
+### Publish a new release for the Emacs package
 Releases are built automatically on each commit, and published at [melpa.org].
-Stable releases are built from each tag, but do update the version number.
+Stable releases are built from each tag, but there are some helpful steps to
+follow for each release.
+
+1. Update the version number in `emacs-live-py-mode/live-py-mode.el`.
+2. Click the README badge for Emacs downloads to see the current number, then
+   update it in the badge's image URL.
 
 ### Debugging live-py-mode in Emacs
 When adding temporary debugging messages with the `message` function, it is

README.md

@@ -5,6 +5,7 @@ Live Coding in Python
 [![HTML Build Status]][actions]
 [![Code Coverage]][codecov]
 [![PyCharm downloads]][pycharm plugin]
+[![Emacs downloads]][emacs plugin]
 [![Sublime downloads]][sublime plugin]
 [![space-tracer downloads]][space-tracer]
 [![DOI]][zenodo]
@@ -19,6 +20,8 @@ even your browser.
 [codecov]: https://codecov.io/github/donkirkby/live-py-plugin?branch=master
 [PyCharm downloads]: https://img.shields.io/jetbrains/plugin/d/9742?label=PyCharm%20%E2%86%93
 [pycharm plugin]: https://plugins.jetbrains.com/plugin/9742
+[Emacs downloads]: https://img.shields.io/badge/Emacs%20%E2%86%93-362k-brightgreen
+[emacs plugin]: https://melpa.org/#/live-py-mode
 [Sublime downloads]: https://img.shields.io/packagecontrol/dt/Live%20Coding%20in%20Python?label=Sublime%20%E2%86%93
 [sublime plugin]: https://packagecontrol.io/packages/Live%20Coding%20in%20Python
 [space-tracer downloads]: https://static.pepy.tech/personalized-badge/space-tracer?left_color=grey&right_color=brightgreen&left_text=space-tracer%20%E2%86%93