Modify reponame to PLUGIN and fix some typos

Signed-off-by: yuexiao-wang <wang.yuexiao@zte.com.cn>
Upstream-commit: f93df409b4
Component: cli

components/cli/docs/reference/commandline/plugin_create.md

@@ -16,7 +16,7 @@ keywords: "plugin, create"
 # plugin create
 
 ```markdown
-Usage:  docker plugin create [OPTIONS] reponame[:tag] PATH-TO-ROOTFS
+Usage:  docker plugin create [OPTIONS] PLUGIN[:tag] PATH-TO-ROOTFS(rootfs + config.json)
 
 Create a plugin from a rootfs and configuration
 

components/cli/docs/reference/commandline/plugin_push.md

@@ -14,7 +14,7 @@ keywords: "plugin, push"
 -->
 
 ```markdown
-Usage:  docker plugin push NAME[:TAG]
+Usage:  docker plugin push PLUGIN[:TAG]
 
 Push a plugin to a registry