adding microshift to the main distro map

Author: kalexand-rh

_distro_map.yml

@@ -243,3 +243,13 @@ openshift-acs:
     rhacs-docs-3.72:
       name: '3.72'
       dir: acs/3.72
+microshift:
+  name: MicroShift
+  author: OpenShift Documentation Project <[email protected]>
+  site: commercial
+  site_name: Documentation
+  site_url: https://docs.openshift.com/
+  branches:
+    enterprise-4.12:
+      name: '4.12'
+      dir: microshift/4.12