docs: remove zulip references (#8109)

docs/index.md

@@ -1,4 +1,4 @@
-# electron-builder [![npm version](https://img.shields.io/npm/v/electron-builder.svg?label=latest)](https://yarn.pm/electron-builder) [![downloads per month](https://img.shields.io/npm/dm/electron-builder.svg)](https://yarn.pm/electron-builder) [![donate](https://img.shields.io/badge/donate-donorbox-green.svg)](https://www.electron.build/donate) [![project chat](https://img.shields.io/badge/chat-on_zulip-brightgreen.svg)](https://electron-builder.zulipchat.com)
+# electron-builder [![npm version](https://img.shields.io/npm/v/electron-builder.svg?label=latest)](https://yarn.pm/electron-builder) [![downloads per month](https://img.shields.io/npm/dm/electron-builder.svg)](https://yarn.pm/electron-builder) [![donate](https://img.shields.io/badge/donate-donorbox-green.svg)](https://www.electron.build/donate)
 A complete solution to package and build a ready for distribution Electron app for macOS, Windows and Linux with “auto update” support out of the box.
 
 * NPM packages management:
@@ -25,7 +25,7 @@ A complete solution to package and build a ready for distribution Electron app f
 | Question | Answer |
 |--------|-------|
 | “I want to configure electron-builder” | [See options](configuration/configuration.md) |
-| “I have a question” | [Open an issue](https://github.com/electron-userland/electron-builder/issues) or [join the chat](https://electron-builder.zulipchat.com/) |
+| “I have a question” | [Open an issue](https://github.com/electron-userland/electron-builder/issues) |
 | “I found a bug” | [Open an issue](https://github.com/electron-userland/electron-builder/issues/new) |
 | “I want to support development” | [Donate](donate.md) |