Allow registering custom templates

[eliezermarques]

Prerequisites

• I have read the documentation;
• In the case of a bug report, I understand that providing a SSCCE example is tremendously useful to the maintainers.
• Ideally, I'm providing a sample JSFiddle or a shared playground link demonstrating the issue.

Description

It would be great to also be able to register our object and array templates, just like it is possible for widgets.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Please leave a comment if this is still an issue for you. Thank you.