Support strings, not just URLs

[ajmeese7]

Is your feature request related to a problem? Please describe.
For example, I am going to help this fellow on Stack Overflow, who wants their rules fixed for modifying the content of a page. But the tool doesn't have an option to paste content without a hosting URL.

Describe the solution you'd like
A way to use raw text for testing the .htaccess rules, specifically useful for rules pertaining to mod_substitute.