Add instructions about npm

Author: rafaelfranca

README.md

@@ -42,6 +42,11 @@ Require both `jquery` and `jquery_ujs` into your application.js manifest.
 //= require jquery_ujs
 ```
 
+Installation using npm.
+------------
+
+Run `npm install --save jquery-ujs` to install the jquery-ujs package.
+
 Installation using Bower
 ------------
 

RELEASE.md

@@ -0,0 +1,23 @@
+## Releasing jquery-ujs
+
+### Releasing to npm
+
+Make sure npm's configuration `sign-git-tag` is set to true.
+
+```
+npm config set sign-git-tag true
+```
+
+Release it to npm using the [npm version command](https://docs.npmjs.com/cli/version). Like:
+
+```
+npm version patch
+```
+
+This will:
+
+* Bump a patch version
+* Commit the change
+* Generate the tag
+* Push the commit and the tag to the repository
+* Publish the package in https://www.npmjs.com