Update publish command

U; Please enter the commit message for your changes. Lines starting

Author: PowerKiKi

README.md

@@ -67,7 +67,7 @@ The most useful commands for development are:
 
 - `yarn dev` to start a development server
 - `yarn build-demo` to build the demo locally (it will be published automatically by Travis)
-- `git -a 1.2.3 && git push` to publish the lib to npm (via Travis deploy mechanism)
+- `git tag -a 1.2.3 && git push` to publish the lib to npm (via Travis deploy mechanism)
 
 ## TODO List