fix chatting in README

README.md

@@ -76,9 +76,7 @@ folder for further examples.
 
 If you encounter bugs, want to suggest new features or have questions, feel free
 to [open an issue](https://github.com/JuliaReach/RangeEnclosures.jl/issues/new).
-You can also chat with the package developers on
-[Gitter](https://gitter.im/JuliaReach/Lobby?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
-or in the `#reachability-analysis` stream on
+You can also chat with the package developers at the `#juliareach` stream on
 [Zulip](https://julialang.zulipchat.com/). Pull requests implementing new
 features or fixing bugs are also welcome. Make sure to check out the
 [contribution guidelines](https://juliareach.github.io/RangeEnclosures.jl/dev/about/#Contributing-1).