[PATCH] Document ${(!)refname}

[Bart Schaefer <schaefer@xxxxxxxxxxxxxxxx>]

This documents workers/51509.

diff --git a/Doc/Zsh/expn.yo b/Doc/Zsh/expn.yo
index 7bc736470..418139424 100644
--- a/Doc/Zsh/expn.yo
+++ b/Doc/Zsh/expn.yo
@@ -987,6 +987,11 @@ means the same thing as the more readable
`(tt(%%qqq))'.  The
 following flags are supported:

 startitem()
+item(tt(!))(
+When the parameter being expanded is a named reference, the reference
+string is substituted and thus the reference is em(not) resolved.  In
+ksh emulation, the parens around this flag are optional.
+)
 item(tt(#))(
 Evaluate the resulting words as numeric expressions and interpret
 these as character codes.  Output the corresponding characters.  Note