🐛 Custom modifications to the blocks atlas gets cleared when exporting #470

🛑 Before you Start

• I have searched existing bug reports for my problem.
• I have read the F-A-Q.
• I am using the latest version of Animated Java
• I will only report a single bug in this report. If I have found multiple bugs, I will create a separate report for each one.

🗣️ Describe the bug

Pretty sure this is the same issue as the one with pack.meta, but when you add your own custom directories the the blocks.json file it gets cleared with only the blueprint directory being left

⚠️ Error Message

🔄️ How to Reproduce

Put any custom directory in the generated blocks.json within minecraft/atases, for example:

{
	"sources": [
		{
			"type": "directory",
			"source": "blueprint",
			"prefix": "blueprint/"
		},
		{
			"type": "directory",
			"source": "upgrade",
			"prefix": "upgrade/"
		}
	]
}

Export a model, and it will clear:

{
	"sources": [
		{
			"type": "directory",
			"source": "blueprint",
			"prefix": "blueprint/"
		}
	]
}

✅ Expected Behavior

For it to not be cleared

💡 Solutions & Alternatives

I am currently just canceling the change using version control, but it would be nice to not have to do so.

🟩 Minecraft Version

1.20.5

🟦 Blockbench Version

4.12.6

💻 Operating System

Windows

📃 Installed Blockbench Plugins

No response

⛰️ Minecraft Environment

No response