Implement contextual documentation link for document types in experience manager

Document types:

• As a developer, I would like to set custom documentation links for document types in the console so that editors and authors can refer to these links when they need help. 
• As an editor/author, I’d like to see the specific documentation links in the component properties as read only meta-data so that I can refer to related documentation while I’m authoring

Document types

• Introduce a new meta-data for document types which can be added through console by developers
• The developer can set a specific URL on the metadata for their custom documentation per document type
• This meta-data should be only read only for editors and authors in the CMS
• When editors/authors click on the icon which includes the URL, it should open the customers documentation site on a new tab outside of the CMS.
• Show a tooltip when user hovers over the icon “Internal Documentation”
• The documentation link icon will not be shown if the documentation link is not set by the developer in the console.

Designs and changes agreed on the cycle planning on Nov 2:

• The placement of the link will be in the "i" icon on the top right corner as shown in the design below

• The "i" icon should be replaced with the "?" icon used in the help menu in the left hand side navigation menu