tilegen.py tileset and tilemap generator

Hi!

This is a feature that TileStudio had integrated and I always missed to have in Tiled when I tried Tiled. So it's very welcome even if it's a standalone script.
Probably I can add it to the Gimp plugins too, so you can open(or edit) the image with Gimp, and export the Tileset/Tilemap.

Thx!

Ok, fixed the walrus problem by re-writing the 3 lines using it in the old style
Then it complained about then check_calls... maybe for the same reason, too news python? So I commented the try lines, as I know ImageMagick is already on my system. And tho it still complains (ImageMagick says something about gray imanges(?) ) it works
Next time I'll change it to also support a more standard .bin pure binary data export, Thanks for the toy! I'm pretty much sure I'll use it many times. That was almost the last step to don't depend on TileStudio (wich I like, but makes me use wine :-P )

Not sure what PR is. Private message or so? Not sure if there is any.
So easier... I changed

#if not (tile_dim := re.search('(\d+)x(\d+)', sys.argv[2])):  #<- this
tile_dim = re.search('(\d+)x(\d+)', sys.argv[2])   #<- to this
if not (tile_dim):
#if not (tileset_dim := re.search('(\d+)x(\d+)', sys.argv[4])):  #< this
tileset_dim = re.search('(\d+)x(\d+)', sys.argv[4]) #<- to this
if not (tileset_dim):
#tile_num = match.group(0) if (match := re.search("[0-9]+", filename)) else None  #< this
match = re.search("[0-9]+", filename)  #<- to this
tile_num = match.group(0) if (match) else None

This way Python 3.7 likes it. I should update someday, but in the time, and for my own use, it works.
also commented all this, for same reasons

    """ 
    try:
        check_call(['convert', '-help'], stdout=DEVNULL, stderr=STDOUT)
    except FileNotFoundError:
        sys.exit('Install ImageMagick or put magick in your path')

    try:
        check_call(['identify', '-help'], stdout=DEVNULL, stderr=STDOUT)
    except FileNotFoundError:
        sys.exit('Install ImageMagick or put identify in your path')

    try:
        check_call(['convert', '-help'], stdout=DEVNULL, stderr=STDOUT)
    except FileNotFoundError:
        sys.exit('Install ImageMagick or put convert in your path')
    """

hi, did you take into account the infamous color clash in screen 2/4 modes?
did you try to map the original color into the msx1 fixed palette or to reduce the number of colors to 15 and reconfigure the palette if used on msx2?

The tool won't convert. Its not the purpose. It only creates the minimal tilset from a bigger image and the map to recreate it. Its up to you to convert the tileset one way or another. I do it with Gimp, usually.