Check file existence

[mantir]

Is your feature request related to a problem? Please describe.
The problem is that I need to check if a file exists in a subfolder and if my .htaccess works for that.

Describe the solution you'd like
I would like to have a fake fileexplorer where I can add files and folders. For security reasons the file content should always just be the path to the file.

Thanks for the great work so far!

[bradkane]

Another solution already proposed: #7 (comment)