Add a warning on image names witth `#`

[vict0rsch]

there seems to be a processing on #. I have a file with name train_r_s_12_#0_step_12.png which gets processed into (1) val_s_s_12_-0_step_12-by-omniart.jpg but accessed using the original name, i.e train_r_s_12_#0_step_12-by-omniart.jpg (2)

So deployed website cannot match the required ressource (1) to the actual file (2)

[vict0rsch]

I'll just rename my files but a warning would be nice

[thasophearak]

👋 @vict0rsch thank for the issue!

the file name is rewrite with https://github.com/gosimple/slug, my guess is that, throughout image processing flow, there must be one part that missed used.

Will try to find and fix it.