This commit improves the reference document to better reflect the
different between `*` or `{name}` on one side, and `**` or `{*path}` on
the other.
The former patterns only consider a single path segment and its content,
while the latter variants consider zero or more path segments. This
explains why `/test/{*path}` can match `/test`.
Closes gh-35727
Brian Clozel
8bb63081a8