[custom map suggestion] extend {s} parameter with numeric enumeration

[mallybiky]

The custom map suggestion is very nice to use but the enumeration only uses a, b or c in the loop. The "here base" does use number 1, 2, 3 and 4 this this so the maptiles can't be loaded. It would be nice to be specify the looping letters/numbers.

[mallybiky]

Also viamichelin.com uses numbers 1, 2 and 3.

[vcoppe]

Thank you for your suggestion, I have re-implemented the website from scratch and added that to the future version.
You can check it out here: https://gpx.studio/gpx.studio/ and provide feedback on this new repository: https://github.com/gpxstudio/gpx.studio.