Use GitHub Discussions over Gitter

GH Discussions support upvoting threads and upvoting. Features
lacking in Gitter. Gitter is also less activate.

README.md

@@ -1,12 +1,12 @@
 PyAV
 ====
 
-[![GitHub Test Status][github-tests-badge]][github-tests]
-[![Gitter Chat][gitter-badge]][gitter] [![Documentation][docs-badge]][docs] \
-[![Python Package Index][pypi-badge]][pypi] [![Conda Forge][conda-badge]][conda]
-
 PyAV is a Pythonic binding for the [FFmpeg][ffmpeg] libraries. We aim to provide all of the power and control of the underlying library, but manage the gritty details as much as possible.
 
+---
+
+[![GitHub Test Status][github-tests-badge]][github-tests] [![Documentation][docs-badge]][docs] [![Python Package Index][pypi-badge]][pypi] [![Conda Forge][conda-badge]][conda]
+
 PyAV is for direct and precise access to your media via containers, streams, packets, codecs, and frames. It exposes a few transformations of that data, and helps you get your data to/from other packages (e.g. Numpy and Pillow).
 
 This power does come with some responsibility as working with media is horrendously complicated and PyAV can't abstract it away or make all the best decisions for you. If the `ffmpeg` command does the job without you bending over backwards, PyAV is likely going to be more of a hindrance than a help.
@@ -66,18 +66,17 @@ pip install .
 
 ---
 
-Have fun, [read the docs][docs], [come chat with us][gitter], and good luck!
+Have fun, [read the docs][docs], [come chat with us][discuss], and good luck!
 
 
 
 [conda-badge]: https://img.shields.io/conda/vn/conda-forge/av.svg?colorB=CCB39A
 [conda]: https://anaconda.org/conda-forge/av
 [docs-badge]: https://img.shields.io/badge/docs-on%20pyav.basswood--io.com-blue.svg
 [docs]: https://pyav.basswood-io.com
-[gitter-badge]: https://img.shields.io/gitter/room/nwjs/nw.js.svg?logo=gitter&colorB=cc2b5e
-[gitter]: https://app.gitter.im/#/room/#PyAV-Org_User-Help:gitter.im
 [pypi-badge]: https://img.shields.io/pypi/v/av.svg?colorB=CCB39A
 [pypi]: https://pypi.org/project/av
+[discuss]: https://github.com/PyAV-Org/PyAV/discussions
 
 [github-tests-badge]: https://github.com/PyAV-Org/PyAV/workflows/tests/badge.svg
 [github-tests]: https://github.com/PyAV-Org/PyAV/actions?workflow=tests