add docs on publishing new release (#36)

Author: natalyapeixoto

PUBLISHING.md

@@ -0,0 +1,7 @@
+### Publish on NPM 
+
+- [login to your npm account](http://npm.github.io/installation-setup-docs/installing/logging-in-and-out.html)
+- make sure to update the version of the package on `package.json`
+- inside projects folder run `npm publish` 
+- on github download the code to your machine and upload it to create a new release 
+<img src="./docs/releases.png">