gnmic: add page and subpages (#8367)

* gnmic - add

* Change file extension

* Fix newlines

* update gnmic pages and add gnmic sub alias

* fix link

* add period

* fix missing punctuation

* fix ip:port formatting

* Implemented @adrienthebo suggestions

* missing period

* @EmilySeville7cfg suggestions

* remove --insecure and write out sub

pages/common/gnmic-set.md

@@ -0,0 +1,20 @@
+# gnmic set
+
+> Modify gnmi network device configuration.
+> More information: <https://gnmic.kmrd.dev/cmd/set>.
+
+- Update the value of a path:
+
+`gnmic --address {{ip:port}} set --update-path {{path}} --update-value {{value}}`
+
+- Update the value of a path to match the contents of a json file:
+
+`gnmic -a {{ip:port}} set --update-path {{path}} --update-file {{filepath}}`
+
+- Replace the value of a path to match the contents of a json file:
+
+`gnmic -a {{ip:port}} set --replace-path {{path}} --replace-file {{filepath}}`
+
+- Delete the node at a given path:
+
+`gnmic -a {{ip:port}} set --delete {{path}}`