Add permanent scope ignore for images

[harinee]

Is your feature request related to a problem? Please describe.
Currently image files fail Talisman checks, although this wouldn't be a place to enter secrets

Describe the solution you'd like
Image files with extensions .jpeg, .jpg, .png, .tiff, .bmp should be added to the permanent ignore feature within Talisman

Additional context
This will be an addition to Talisman's permanent ignore feature from #122

[arunvelsriram]

I am going to take a stab at this.

[arunvelsriram]

Currently image files fail Talisman checks, although this wouldn't be a place to enter secrets

I am not able to repelicate this.

[dcRUSTy]

Currently image files fail Talisman checks, although this wouldn't be a place to enter secrets

I am not able to repelicate this.

Not exactly matches with the issue title. This may be another possibility https://en.wikipedia.org/wiki/Data_URI_scheme#HTML

[harinee]

Sorry for chiming in so late, but I just found a repo where it is reproducible.
https://github.com/harinee/blog-me
Run a talisman --scan here.
It is a simple HTML/CSS repo. It has a bunch of images, and talisman highlights them as issues, such as "results":[{"filename":"images/avatars/user-04.jpg","failure_list":[{"type":"filecontent","message":"Expected file to not to contain hex encoded texts such as: xmpMM:DocumentID=\"xmp.did:0D158A1E5A1811E590A58...",

[tw-owen-nelson]

This was completed by #312