public release 2.2.0 - see README.md and CHANGES.md for details

README.md

@@ -16,7 +16,7 @@ Highlights
 
 - angle or energy scanned XPD.
 - various scanning modes including energy, polar angle, azimuthal angle, analyser angle.
-- averaging over multiple symmetries (domains or emitters).
+- averaging over multiple domains and emitters.
 - global optimization of multiple scans.
 - structural optimization algorithms: particle swarm optimization, grid search, gradient search.
 - calculation of the modulation function.
@@ -38,6 +38,12 @@ Detailed installation instructions and dependencies can be found in the document
 (docs/src/installation.dox).
 A [Doxygen](http://www.stack.nl/~dimitri/doxygen/index.html) compiler with Doxypy is required to generate the documentation in HTML or LaTeX format.
 
+The easiest way to set up an environment with all dependencies and without side-effects on other installed software is to use a [Singularity](https://www.sylabs.io/guides/2.5/user-guide/index.html) container.
+A Singularity recipe file is part of the distribution, see the PMSCO documentation for details.
+On newer Linux systems (e.g. Ubuntu 18.04), Singularity is available from the package manager. 
+Installation in a [virtual box](https://www.virtualbox.org/) on Windows or Mac is straightforward using the [Vagrant](https://www.vagrantup.com/) system.
+A Vagrant file is included in the distribution.
+
 The public distribution of PMSCO does not contain the [EDAC](http://garciadeabajos-group.icfo.es/widgets/edac/) code.
 Please obtain the EDAC source code from the original author, copy it to the pmsco/edac directory, and apply the edac_all.patch patch.
 
@@ -61,7 +67,7 @@ Matthias Muntwiler, <mailto:matthias.muntwiler@psi.ch>
 Copyright
 ---------
 
-Copyright 2015-2018 by [Paul Scherrer Institut](http://www.psi.ch)
+Copyright 2015-2020 by [Paul Scherrer Institut](http://www.psi.ch)
 
 
 Release Notes