MAINT: Added version to docs.

Not increasing version number, because nothing was changed at the code level.

src/doc/conf.py

@@ -27,9 +27,9 @@ copyright = '2021, IndiScale GmbH'
 author = 'Daniel Hornung'
 
 # The short X.Y version
-version = '0.X.Y'
+version = '0.3.1'
 # The full version, including alpha/beta/rc tags
-release = '0.x.y-beta-rc2'
+release = '0.3.1'
 
 
 # -- General configuration ---------------------------------------------------