Metainfo: Add contact and vcs-browser URLs, update deprecated SPDX li…

…cense identifier (#45)

Sources/project.metainfo.xml

@@ -4,7 +4,7 @@
 	<name>Jazz² Resurrection</name>
 	<summary>A re-implementation of Jazz Jackrabbit 2</summary>
 	<metadata_license>CC0-1.0</metadata_license>
-	<project_license>GPL-3.0+</project_license>
+	<project_license>GPL-3.0-or-later</project_license>
 	<developer_name>Daniel Rajf</developer_name>
 	<developer id="deat.tk">
 		<name>Daniel Rajf</name>
@@ -42,6 +42,8 @@
 	<url type="homepage">https://deat.tk/jazz2/</url>
 	<url type="bugtracker">https://github.com/deathkiller/jazz2-native/issues</url>
 	<url type="faq">https://deat.tk/jazz2/help</url>
+	<url type="contact">https://discord.gg/Y7SBvkD</url>
+	<url type="vcs-browser">https://github.com/deathkiller/jazz2-native</url>
 
 	<screenshots>
 		<screenshot type="default">