In twenty-something years of game development, I have never seen anyone use tiles as individual files. Using a single tile sheet/tile atlas comes with tremendous opportunities for optimization. In the end, you want to create efficiently laid-out texture pages with all of your tiles and sprites. You then reference the UV coordinates of the sprite/tile(s) on the texture page when you need to draw one. This minimizes costly file operations, unnecessary texture page swaps, and much more than I can realistically cover in a quick comment.
If you're using a game engine, it almost certainly supports tile maps/tile atlases with some kind of native functionality.
If you're drawing to the canvas manually, you should still be using this fundamental approach to implementing tile systems. It's been refined over many years by many intelligent developers.
See: https://developer.mozilla.org/en-US/docs/Games/Techniques/Tilemaps
Please know, I'm not trying to shame you; we all start somewhere.
My point is two-fold:
1) If you're asking for separate files for each tile, you aren't working optimally. In fact, very much the opposite.
2) It's an unreasonable expectation to put on the creator of this asset. No one else is going to need individual files, not if they know what they're doing. So you're asking for a lot of tedious work, at no extra cost, for something only you require.
I genuinely hope this was helpful.