Copy the "Note about /" note from the Location

explanation to the LocationMatch explanation.
Probably more people use LocationMatch than
Location with "~".

CTR: docs

Backport of r1851790 from trunk.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1851792 13f79535-47bb-0310-9956-ffa450edef68