Switch to 1.20.1

Given we're doing a release to address bugs introduced in 1.20.1,
I think that we should mark the nexte version as a patch release.

Signed-off-by: David Thompson <davthomp@redhat.com>

Author: datho7561

package-lock.json

@@ -15,7 +15,7 @@
     }
   ],
   "license": "MIT",
-  "version": "1.21.0",
+  "version": "1.20.1",
   "publisher": "redhat",
   "bugs": "https://github.com/redhat-developer/vscode-yaml/issues",
   "repository": {