adding meta tags to head with javascript

gistfile1.js

var meta=document.createElement('meta');
meta.name='viewport';

meta.setAttribute('content', 'width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=0');

document.getElementsByTagName('head')[0].appendChild(meta);

I had the option to add the tag using article_page.hbs file. This file runs on every article in my Zendesk Help Center.
All I had to do was add the following to the beginning of that file:

{{#each article.labels}}
{{#is identifier 'noindex'}}<meta name="robots" content="noindex">{{/is}}
{{/each}}