[ci skip] update readme.

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>

README.md

@@ -47,8 +47,8 @@ docker run --rm \
   -e PLUGIN_PASSWORD=xxxxxxx \
   -e PLUGIN_PORT=xxxxxxx \
   -e PLUGIN_KEY="$(cat ${HOME}/.ssh/id_rsa)"
-  -e PLUGIN_SOURCE=xxxxxxx \
-  -e PLUGIN_TARGET=xxxxxxx \
+  -e PLUGIN_SOURCE=SOURCE_FILE_LIST \
+  -e PLUGIN_TARGET=TARGET_FOLDER_PATH \
   -e DRONE_REPO_OWNER=appleboy \
   -e DRONE_REPO_NAME=go-hello \
   -e DRONE_COMMIT_SHA=e5e82b5eb3737205c25955dcc3dcacc839b7be52 \