Add appdata

org.gnome.Platform.appdata.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<!-- Copyright 2017 Richard Hughes <richard@hughsie.com> -->
+<component type="runtime">
+  <id>org.gnome.Platform</id>
+  <metadata_license>CC0</metadata_license>
+  <!-- FIXME -->
+  <project_license>GPL-2.0+</project_license>
+  <name>GNOME Application Platform</name>
+  <summary>Shared libraries used by GNOME applications</summary>
+  <url type="homepage">http://www.gnome.org/</url>
+  <project_group>GNOME</project_group>
+</component>
+

org.gnome.Sdk.appdata.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<!-- Copyright 2017 Richard Hughes <richard@hughsie.com> -->
+<component type="runtime">
+  <id>org.gnome.Sdk</id>
+  <metadata_license>CC0</metadata_license>
+  <!-- FIXME -->
+  <project_license>GPL-2.0+</project_license>
+  <name>GNOME Software Development Kit</name>
+  <summary>Tools and headers for developing applications using the GNOME application platform</summary>
+  <url type="homepage">http://www.gnome.org/</url>
+  <project_group>GNOME</project_group>
+</component>
+

org.gnome.Sdk.json.in

@@ -788,6 +788,14 @@
                     "type": "file",
                     "path": "os-release"
                 },
+                {
+                    "type": "file",
+                    "path": "org.gnome.Sdk.appdata.xml"
+                },
+                {
+                    "type": "file",
+                    "path": "org.gnome.Platform.appdata.xml"
+                },
                 {
                     "type": "file",
                     "path": "os-release-configure",

os-release-configure

@@ -4,6 +4,11 @@ cat <<EOF > Makefile
 all:
 
 install:
-	mkdir -p $(DESTDIR)/usr/lib
-	install os-release $(DESTDIR)/usr/lib
+	mkdir -p ${DESTDIR}/usr/lib
+	install os-release ${DESTDIR}/usr/lib
+	mkdir -p ${DESTDIR}/usr/share/appdata
+	install org.gnome.Platform.appdata.xml ${DESTDIR}/usr/share/appdata
+	install org.gnome.Sdk.appdata.xml ${DESTDIR}/usr/share/appdata
+	appstream-compose --basename=org.gnome.Platform --prefix=/usr --origin=flatpak org.gnome.Platform
+	appstream-compose --basename=org.gnome.Sdk --prefix=/usr --origin=flatpak org.gnome.Sdk
 EOF