Fix error in explanation of the interaction between $ and MULTILINE mode.
Reported by Steve Alexander.
diff --git a/Doc/lib/libre.tex b/Doc/lib/libre.tex
index 37c249e..1c14072 100644
--- a/Doc/lib/libre.tex
+++ b/Doc/lib/libre.tex
@@ -101,7 +101,7 @@
newline at the end of the string, and in \constant{MULTILINE} mode
also matches before a newline. \regexp{foo} matches both 'foo' and
'foobar', while the regular expression \regexp{foo\$} matches only
-'foo'. More interestingly, searching for \regexp{foo\$} in
+'foo'. More interestingly, searching for \regexp{foo.\$} in
'foo1\textbackslash nfoo2\textbackslash n' matches 'foo2' normally,
but 'foo1' in \constant{MULTILINE} mode.