Adopt Lottie as the project's file format
Hi, about https://github.com/friction2d/friction/issues/440 which discusses the creation of an XML-parsed project file. I don't think I personally agree with switching to XML, as it's much slower to open and that's noticeable in an animation program.
BUT, if you're switching to a plain-text format, why not use Lottie? It's a universal file format that is already compatible with other programs, such as Synfig.