To run in development mode, change `MATTERMOST_REMOTE` in `rundev.sh` to a server where you have an
account, then execute `rundev.sh`.
This will start a web server, and mitmproxy to avoid CORS problems.
Dependencies for that: Bash, Python and [`mitmproxy`](https://mitmproxy.org/).

Then open http://localhost:8000/ in your browser.