showing pre build step

test.uplugin

{
	"FileVersion": 3,
	"Version": 1,
	"VersionName": "0.1.0",
	"FriendlyName": "test plugin,
	"Description": "",
	"Category": "",
	"CreatedBy": "Sammy James",
	"CreatedByURL": "",
	"DocsURL": "",
	"MarketplaceURL": "",
	"SupportURL": "",
	"CanContainContent": false,
	"IsBetaVersion": false,
	"Installed": false,
	"EnabledByDefault": true,
	"Modules": [
		{
			"Name": "SomeModule",
			"Type": "Runtime",
			"LoadingPhase": "PostDefault"
		}
	],
	"PreBuildSteps": {
		"Linux": [
			"cargo build --manifest-path $(PluginDir)/Source/example/Cargo.toml"
		],
		"Win64": [],
		"MacOS": []
	}
}