The second number stands for the image hash generated by the imagesim library. Each line is a new image entry.
If you have your images saved locally, create an images folder in the same directory as the main file. It will index all images inside that folder and put them into database.txt (if it does not exist). Currently it only supports PNG and JPEG formats.
command-line arguments (-h)
-embed
specifies whether templates and CSS should be embedded into the executable (default true)
-path string
path to database file (default "database.txt")
-port uint
port to start Gin on (default 8080)
-release
specifies whether Gin should run in release mode (default true)
-serve-images
specifies whether the images/ folder should be served