Deploy to a new Glitch app for user remixing from Console

[sebbes-at-deepgram]

Currently: There is a Glitch app which is maintained in sync with this repo thanks to some Github action.

Issue: when the user remix this glitch project from console, they see the current README, which can be disturbing since this README explain how to... remix the project!

What this PR does: in addition of the previous mentioned Glitch app, we also push this repository to another glitch app but with a modified README, so the user can have really nice & adapted instructions to run the demo.

What's not in this PR: the actual README which will be provided later (for now it only consists in a "Test" text). This PR essentially aims to introduce & test the Github action.

Warning: I wasn't able to totally test all the features, and the only way to be totally sure that the configuration is "ok" is to merge into master (which triggers the action). However, if things go wrong, the only bad thing will be a failing action (and more likely the new action I set up), so "not a big deal".