Add community section to pyfar.org

[hoyer-a]

Adds a community section to pyfar.org that includes other packages using pyfar.
For now i would keep all the packages inside the card on the main pyfar.org page. Once the list is longer a subpage would make sense. Also the community sections could be used for other community related content.

Please make suggestions which other packages we should add to the list

[f-brinkmann]

Github provides a probably almost complete list here: https://github.com/pyfar/pyfar/network/dependents (also for our other packages of course). It might make sense to think about critera for listing projects. This would make it straight forward to regularly update the list. E.g. listing all packages that are on pypi and not obviously discontinued, and listing all non pypi repositorys with a certain number of forks or stars.