How to add new Tileset without a tsx file

When I add a new tileset to my map, it wants to save the tileset as a ‘tsx’ file. But for my older tilesets in the map, there is no ‘tsx’ file. The map XML just lists the image and the number of tiles, etc directly in the map xml. That’s what I want. I don’t want a reference to some external file I have to open to get the simple number of tiles in the set. How do I add a new tileset to my map so that it is listed the old way in my map?

I could edit the xml by hand I suppose, but going forward I am going to be editing dozens of maps. Is there some way of just having it list the tileset information directly in the map? Why is a separate file needed for basically two extra numbers?

Check “Embed in map” when creating the tileset.
If you already created the tileset, there are little Embed and Export buttons in the Tilesets view.

It’s easier to share the “external” tilesets across several maps.
A tileset can be more than just two numbers. It could have tile properties, or terrain information, or it could be a collection of individual images where the tiles can different sizes. Of course, not everyone has to use the extra features :‍)

Yet another option is to check “Embed tilesets” in the export options. That way you could use an external tileset for editing, but export a self-contained map.