Add PWA link to unstable versions of the Configurator on README (#3886)

* Add PWA link to unstable versions of the Configurator on README

Add a link to the PWA version of the Configurator, under "Unstable Testing Versions".

* Fix typo in README

Co-authored-by: Mark Haslinghuis <[email protected]>

* Replace Slack information with Discord

The text is the same than we have in the Betaflight firmware README.

---------

Co-authored-by: Mark Haslinghuis <[email protected]>

README.md

@@ -2,7 +2,7 @@
 
 ![Betaflight](http://static.rcgroups.net/forums/attachments/6/1/0/3/7/6/a9088900-228-bf_logo.jpg)
 
-[![Latest version](https://img.shields.io/github/v/release/betaflight/betaflight-configurator)](https://github.com/betaflight/betaflight-configurator/releases) [![Build](https://img.shields.io/github/actions/workflow/status/betaflight/betaflight-configurator/nightly.yml?branch=master)](https://github.com/betaflight/betaflight-configurator/actions/workflows/nightly.yml) [![Crowdin](https://d322cqt584bo4o.cloudfront.net/betaflight-configurator/localized.svg)](https://crowdin.com/project/betaflight-configurator) [![Quality Gate Status](https://sonarcloud.io/api/project_badges/measure?project=betaflight_betaflight-configurator&metric=alert_status)](https://sonarcloud.io/dashboard?id=betaflight_betaflight-configurator) [![License: GPL v3](https://img.shields.io/badge/License-GPLv3-blue.svg)](https://www.gnu.org/licenses/gpl-3.0)
+[![Latest version](https://img.shields.io/github/v/release/betaflight/betaflight-configurator)](https://github.com/betaflight/betaflight-configurator/releases) [![Build](https://img.shields.io/github/actions/workflow/status/betaflight/betaflight-configurator/nightly.yml?branch=master)](https://github.com/betaflight/betaflight-configurator/actions/workflows/nightly.yml) [![Crowdin](https://d322cqt584bo4o.cloudfront.net/betaflight-configurator/localized.svg)](https://crowdin.com/project/betaflight-configurator) [![Quality Gate Status](https://sonarcloud.io/api/project_badges/measure?project=betaflight_betaflight-configurator&metric=alert_status)](https://sonarcloud.io/dashboard?id=betaflight_betaflight-configurator) [![License: GPL v3](https://img.shields.io/badge/License-GPLv3-blue.svg)](https://www.gnu.org/licenses/gpl-3.0) [![Join us on Discord!](https://img.shields.io/discord/868013470023548938)](https://discord.gg/n4E6ak4u3c)
 
 
 Betaflight Configurator is a crossplatform configuration tool for the Betaflight flight control system.
@@ -65,6 +65,8 @@ If you experience graphics display problems or smudged/dithered fonts display is
 
 Unstable testing versions of the latest builds of the configurator for most platforms can be downloaded from [here](https://github.com/betaflight/betaflight-configurator-nightlies/releases/).
 
+The future of the Configurator is moving to a PWA (Progressive Web Application). In this way it will be easier to maintain specially to support different devices like phones, tablets. etc. Is a work in progress but you can have access to the latest snapshot in PWA way without installing anything [here](https://configurator.betaflight.com/) (take into account that some things don't work and are in development).
+
 **Be aware that these versions are intended for testing / feedback only, and may be buggy or broken, and can cause flight controller settings to be corrupted. Caution is advised when using these versions.**
 
 ## Languages
@@ -148,9 +150,17 @@ You can also use multiple platforms e.g. `yarn gulp <taskname> --osx64 --linux64
 
 You can use the GitHub `Actions` tab in your fork to build binaries as well. Select `Actions`>`Manual Build`>`Run Workflow`. Choose your custom branch and click `Run workflow`. The workflow will dispatch in a few moments and upon completion, the build "Artifacts" will be available for download from within the workflow run.
 
-## Support
+## Support and Developers Channel
+
+There's a dedicated Discord server here:
+
+https://discord.gg/n4E6ak4u3c
+
+We also have a Facebook Group. Join us to get a place to talk about Betaflight, ask configuration questions, or just hang out with fellow pilots.
+
+https://www.facebook.com/groups/betaflightgroup/
 
-If you need help please reach out on the [betaflightgroup](https://betaflightgroup.slack.com) slack channel before raising issues on github. Register and [request slack access here](https://slack.betaflight.com).
+Etiquette: Don't ask to ask and please wait around long enough for a reply - sometimes people are out flying, asleep or at work and can't answer immediately.
 
 ### Issue trackers