keep track of index.skipHash

Author: Byron

src/plumbing/progress.rs

@@ -172,6 +172,10 @@ static GIT_CONFIG: &[Record] = &[
         config: "index.sparse",
         usage: Planned {note: Some("we can read sparse indices and support for it will be added early on")},
     },
+    Record {
+        config: "index.skipHash",
+        usage: Planned {note: Some("important to not unnecessarily reject indices just because they are missing a hash (or it is null)")},
+    },
     Record {
         config: "merge.renormalize",
         usage: Planned {note: Some("once merging is being implemented, renormalization should be respected")},