Add maintainer contact info to README (NeuralEnsemble#683)

* added maintainer contact email

* changed maintainer email to more non spammable email format

Author: CozySocksAlways

README.md

@@ -24,6 +24,7 @@ spike trains, LFP, analog signals. The input-output data format is either
 
 * Documentation: https://elephant.readthedocs.io/en/latest/
 * Mailing list: https://groups.google.com/group/neuralensemble
+* Maintainer: contact[at]python-elephant[dot]org
 
 
 #### Visualization of Elephant analysis objects