Remove outdated references to Brian mailing lists

[ci skip]

README.md

@@ -10,7 +10,7 @@ Documentation for Brian2modelfitting can be found at http://brian2modelfitting.r
 
 Brian2modelfitting is released under the terms of the CeCILL 2.1 license.
 
-Please report issues at the github issue tracker (https://github.com/brian-team/brian2/issues) or at the brian support mailing list (http://groups.google.com/group/briansupport/)
+Please report issues at the github issue tracker (https://github.com/brian-team/brian2modelfitting/issues) or at the brian discussion forum (https://brian.discourse.group)
 
 [![DOI](https://zenodo.org/badge/DOI/10.5281/zenodo.4601961.svg)](https://doi.org/10.5281/zenodo.4601961)
 

docs_sphinx/index.rst

@@ -4,12 +4,9 @@ brian2modelfitting
 The package `.brian2modelfitting` is a tool for parameter fitting of neuron
 models in the `Brian 2 simulator <https://brian2.readthedocs.org>`_.
 
-Please contact us at
-``brian-development@googlegroups.com`` (https://groups.google.com/forum/#!forum/brian-development)
-if you are interested in contributing.
-
-Please report bugs at the `github issue tracker <https://github.com/brian-team/brian2modelfitting/issues>`_ or to
-``briansupport@googlegroups.com`` (https://groups.google.com/forum/#!forum/briansupport).
+Please report bugs at the `github issue tracker <https://github.com/brian-team/brian2modelfitting/issues>`_
+or at the `Brian discussion forum <https://groups.google.com/forum/#!forum/briansupport>`_. The latter is
+also a could place to discuss feature requests or potential contributions.
 
 
 Model fitting