markdown: fix formatting/content typos in migrate man page
1) remove erroneous spaces after leading '**'
2) remove duplicate SYNOPSIS section
@@ -32,9 +32,6 @@ Set a new OCI runtime for all containers.
This can be used after a system upgrade which changes the default OCI runtime to move all containers to the new runtime.
There are no guarantees that the containers will continue to work under the new runtime, as some runtimes support differing options and configurations.
-## SYNOPSIS
-**podman system migrate**
-
## SEE ALSO
`podman(1)`, `libpod.conf(5)`, `usermod(8)`
