feature: ability to load content from URL

[lucasgonze]

If a URL parameter for content is pre-set on load, the editor contains that content.

Implementation: it is simple to do this with Javascript. It is robust to do this with a server-side script.

To populate the parameter, there could be event-based Javascript constantly updating the current URL with every keystroke. Then the user selects the URL line and does a copy. Or, alternatively, the event handler could be saving the URL to the clipboard with every keystroke.

To populate the parameter there could be a button that converts the current content to the URL parameter and saves it to the clipboard.

[lucasgonze]

https://github.com/alcor/itty-bitty