feat: do not ignore file which contains external repository listing

.gitignore

@@ -1,5 +1,12 @@
-# ignore all workspace files
-/.metadata/
+# ignore all workspace files but external repository listing
+/.metadata/*
+!/.metadata/.plugins
+/.metadata/.plugins/*
+!/.metadata/.plugins/org.eclipse.core.runtime
+/.metadata/.plugins/org.eclipse.core.runtime/*
+!/.metadata/.plugins/org.eclipse.core.runtime/.settings
+/.metadata/.plugins/org.eclipse.core.runtime/.settings/*
+!/.metadata/.plugins/org.eclipse.core.runtime/.settings/com.xilinx.sdk.sw.prefs
 /RemoteSystemsTempFiles/
 .analytics
 .Xil/*