docs: auto generate Dragonfly cli/api docs via code

Signed-off-by: pouchrobot <pouch-dev@list.alibaba-inc.com>

docs/cli_reference/dfdaemon.md

@@ -22,9 +22,11 @@ dfdaemon [flags]
       --localrepo string   temp output dir of dfdaemon
       --maxprocs int       the maximum number of CPUs that the dfdaemon can use (default 4)
       --node strings       specify the addresses(host:port) of supernodes that will be passed to dfget.
+      --peerPort uint      peerserver will listen the port
       --port uint          dfdaemon will listen the port (default 65001)
       --ratelimit rate     net speed limit (default 20MB)
       --registry string    registry mirror url, which will override the registry mirror settings in the config file if presented (default "https://index.docker.io")
+      --streamMode         dfdaemon will run in stream mode
       --verbose            verbose
       --workHome string    the work home directory of dfdaemon. (default "/root/.small-dragonfly")
 ```