Update Readme for ES5 users?

[bosticka]

I am not using ES6 at all so the import examples do not help me. To get it working for me, I had to use:

angular
    .module('module', [
        'ngSanitize',
        'ng1bs4.library'
    ]);

the .library piece was not obvious, had to look at the source code... :)

[IdanCo]

didn't think about it, Thanks for sharing!

Feel free to add any other snippets that might help the the ecmascriptly challenged amongst us.