Walk a path on the blob page from any commit the id names

With both an id and a path the blob page handed back the raw object
the id named, so a commit id gave the commit text itself, while the
plain page looked the path up in that commit's tree. A tag is peeled
to its commit on the way, and the README example of a pinned commit
now uses a form the request checks accept.

1 file changed, 1 insertion, 1 deletion

diff --git a/README.txt b/README.txt
index 5582164..d2eefea 100644
--- a/README.txt
+++ b/README.txt
@@ -192,7 +192,7 @@ Some worked examples, in the url= form.
     ?url=demo/log&h=next               log of the next branch
     ?url=demo/log&qt=author&q=alice    commits authored by alice
     ?url=demo/tree/src&h=v1.0          the src directory at tag v1.0
-    ?url=demo/commit&id=HEAD~3         one commit, pinned
+    ?url=demo/commit&id=v1.0           one commit, pinned to a tag
     ?url=demo/diff&id=main&id2=next    diff between two branches
     ?url=demo/plain/README.md          the raw bytes of one file
     ?url=demo/atom&h=main              the commit feed for a branch