From img/shows/ttXXXXX-1-1.png and img/shows/ttXXXXX-banner.png
To img/shows/ttXXXXX/1-1.png and img/shows/ttXXXXX/banner.png
Rewrite things while we're here
Example of scripts to migrate from old path to new path:
dir="shows"
for file in "$dir"/*; do
# Replace the first - by a / in order to get the new image path
newfile=$(echo "$file" | sed 's/-/\//')
# Delete everything after the first - in order to get the show path
showpath=$(echo "$file" | sed 's/-.*//')
[ ! -d "$showpath" ] && mkdir "$showpath"
mv "$file" "$newfile"
done