doc: publish the documentation for the latest version (#470)

Enables publication of the documentation for version v0.5.1. As the
driver is still in beta, it is sufficient to publish documentation only
for the latest version.

Additionally, v0.5.1 is set as the latest stable version, and the
documentation on the main branch is marked as unstable.

Author: annastuchlik

docs/source/conf.py

@@ -10,10 +10,10 @@
 # -- General configuration ------------------------------------------
 
 # Build documentation for the following tags and branches
-TAGS = []
+TAGS = ["v0.5.1"]
 BRANCHES = ["main"]
-LATEST_VERSION = "main"
-UNSTABLE_VERSIONS = []
+LATEST_VERSION = "v0.5.1"
+UNSTABLE_VERSIONS = ["main"]
 DEPRECATED_VERSIONS = []
 
 # Add any Sphinx extension module names here, as strings.