Add documentation for schema CLI (#1983)
Add documentation for schema CLI (#1983)

*Motivation*

Make sure we document schema CLI

*Solution*

Add the section in pulsar-admin for schemas CLI.

The last `compact` section is duplicated so removed it.
jai1/pulsar,merlimat/pulsar,merlimat/pulsar,merlimat/pulsar,massakam/pulsar,nkurihar/pulsar,merlimat/pulsar,jai1/pulsar,jai1/pulsar,massakam/pulsar,nkurihar/pulsar,jai1/pulsar,ArvinDevel/incubator-pulsar,massakam/pulsar,ArvinDevel/incubator-pulsar,merlimat/pulsar,nkurihar/pulsar,yahoo/pulsar,yahoo/pulsar,yahoo/pulsar,yahoo/pulsar,nkurihar/pulsar,jai1/pulsar,jai1/pulsar,ArvinDevel/incubator-pulsar,massakam/pulsar,massakam/pulsar,ArvinDevel/incubator-pulsar,jai1/pulsar,nkurihar/pulsar,jai1/pulsar,jai1/pulsar,merlimat/pulsar,yahoo/pulsar,ArvinDevel/incubator-pulsar,yahoo/pulsar,nkurihar/pulsar,nkurihar/pulsar,ArvinDevel/incubator-pulsar,massakam/pulsar,nkurihar/pulsar,ArvinDevel/incubator-pulsar,nkurihar/pulsar,ArvinDevel/incubator-pulsar