docs(docs): explain the difference between -tpls and not

- Add documentation on the difference between `-tpls` and the regular
  built scripts

Closes #420
Closes #4125

misc/demo/index.html

@@ -154,7 +154,7 @@ <h3>Files to download</h3>
                     <p>
                         Build files for all directives are distributed in several flavours: minified for production usage, un-minified
                         for development, with or without templates. All the options are described and can be
-                        <a href="https://github.com/angular-ui/bootstrap/tree/gh-pages">downloaded from here</a>.
+                        <a href="https://github.com/angular-ui/bootstrap/tree/gh-pages">downloaded from here</a>. It should be noted that the <code>-tpls</code> files contain the templates bundled in JavaScript, while the regular version does not contain the bundled templates. For more information, check out the FAQ <a href="https://github.com/angular-ui/bootstrap/wiki/FAQ#full-explanation">here</a> and the README <a href="https://github.com/angular-ui/bootstrap/tree/gh-pages#build-files">here</a>.
                     </p>
                     <p>Alternativelly, if you are only interested in a subset of directives, you can
                         <a ng-click="showBuildModal()">create your own build</a>.