Final peer for gateway (#3091) (#3095)

* Peers for Gateway

Signed-off-by: Josh Horton <joshh@us.ibm.com>

* latest 11-29 review updates

Signed-off-by: Josh Horton <joshh@us.ibm.com>

* Final doc for peers topic

Signed-off-by: Josh Horton <joshh@us.ibm.com>

* final doc for peers gateway

Signed-off-by: Josh Horton <joshh@us.ibm.com>

* Andy final review

Signed-off-by: Josh Horton <joshh@us.ibm.com>
(cherry picked from commit 516bc8b)

Co-authored-by: Josh Horton <joshh@us.ibm.com>