tests: document cherry-pick behavior in face of conflicts

diff --git a/t/t6000lib.sh b/t/t6000lib.sh
old mode 100755 (executable)
new mode 100644 (file)
index f55627b..985d517
--- a/t/t6000lib.sh
+++ b/t/t6000lib.sh
@@ -1,3 +1,5 @@
+: included from 6002 and others
+
 [ -d .git/refs/tags ] || mkdir -p .git/refs/tags
 
 :> sed.script