soc/ila/default-tiles.tsx points to a nonexistent file

[mwachs5]

I wanted to use the Tiled application (https://www.mapeditor.org/) to edit the tilemap.tmx file in app-helloworld.

In the app-helloworld, tilemap.tmx file points to default-tiles.tsx:

https://github.com/Spritetm/hadbadge2019_fpgasoc/blob/master/app-helloworld/tilemap.tmx#L3

That file seems to be expecting a png file: https://github.com/Spritetm/hadbadge2019_fpgasoc/blob/master/soc/ipl/default-tiles.tsx#L3

But in the repo is only included a tga file: https://github.com/Spritetm/hadbadge2019_fpgasoc/blob/master/soc/ipl/tileset-default.tga

This causes Tiled application to complain when attempting to edit tilemap.tmx in the hello world demo that it can't find the png file.

If I open the tga file up in macos preview and then export it as a png file, then the Tiled application is happy and I can edit it.

Should the PNG version be added in addition/instead of the tga file? Or should the default-tiles.tsx be edited to look for the tga file instead?