Add Contributing and Questions section to README (#357)

* add Contributing and Questions section to README

* add line breaks

* spaces instead of backslashes

README.md

@@ -17,6 +17,11 @@ You can install Ferrite from the Pkg REPL:
 pkg> add Ferrite
 ```
 
+## Contributing and Questions
+If you have specific questions about Ferrite.jl, you're welcome to reach out to us on the Julia Slack under #ferrite-fem or on Zulip under #Ferrite.jl ([here](https://julialang.org/community/) you can find links to Slack and Zulip). If you encounter a problem, please open an [issue](https://github.com/Ferrite-FEM/Ferrite.jl/issues). Feel free to ask us in case you are not sure if a problem is on the side of Ferrite.jl!  
+Contributions are very welcome, as are feature requests and suggestions.  
+Please keep in mind that we are part of the Julia community and adhere to the [Julia Community Standards](https://julialang.org/community/standards/).
+
 
 [docs-dev-img]: https://img.shields.io/badge/docs-dev-blue.svg
 [docs-dev-url]: http://ferrite-fem.github.io/Ferrite.jl/dev/