[BUG] CFGEditor++ generates json files with 4-space indentations

[Atari2]

Describe the bug
CFGEditor++ generates its json files with 4 spaces of indentation per level, which is inconsistent with the original CFG Editor's 2 spaces of indentation.

To Reproduce
Compare a json file generated by CFG Editor to a json file generated by CFGEditor++

Expected behavior
I would expect both types of CFG Editor to generate the same json file identically, but they differ in whitespace.

[Atari2]

Duplicated from issue

Original comments:

[Atari2]

Unfortunately I've looked and it doesn't seem like Qt offers custom indentation for its JSON deserialization, it only supportes either indented or not indented without specifying how much. I don't want to drop in a third-party JSON parser just for this and I don't want to change the original CFG Editor behavior, so it shall remain as is, for now, unless someone has ideas on how to "fix" this