Merge branch 'master' into v3.0.0

docs/migration

@@ -1,31 +1,38 @@
-
-== Migration from network to domain ==
+Python 2 -> Configuration Migration
+===================================
 
 With the port of OpenNSA from Python 2 to Python 3, support for multiple
 backends was added. For this, some changes in the configuration format was
 needed.
 
+The changes are:
+* Use domain instead of network in ```[service]``` block
+* Each backend must specify a network name in its block
+* NRM Map must now be specified per backend
 
-Old style:
-
+Example of old style:
 
+```
 [service]
 network=aruba.net
 nrmmap=aruba.nrm
 
 [dud]
+```
 
 Equivalent config in new style:
 
+```
 [service]
 domain=aruba.net
 
 [dud:topology]
 nrmmap=aruba.nrm
+```
 
+An example with multiple backends shows why the change was needed:
 
-Multiple backends:
-
+```
 [service]
 domain=aruba.net
 
@@ -34,7 +41,8 @@ nrmmap=aruba-topo1.nrm
 
 [dud:topology1]
 nrmmap=aruba-topo2.nrm
+```
 
 Feel free to call your networks something better than topology, but use
-'topology' if you want to support the old STP names.
+'topology' if you want to keep the old STP names.