docs: mention that boldtext can be overridden also for function tags

doc/nano.texi

@@ -675,9 +675,9 @@ Do backwards searches by default.
 
 @item set boldtext
 Use bold instead of reverse video for the title bar, status bar, key combos,
-line numbers, and selected text.  This can be overridden for the first four
-by setting the options @code{titlecolor}, @code{statuscolor}, @code{keycolor},
-and @code{numbercolor}.
+function tags, line numbers, and selected text.  This can be overridden for
+the first five by setting the options @code{titlecolor}, @code{statuscolor},
+@code{keycolor}, @code{functioncolor}, and @code{numbercolor}.
 
 @item set brackets "@var{string}"
 Set the characters treated as closing brackets when justifying

doc/nanorc.5

@@ -75,9 +75,9 @@ Do backwards searches by default.
 .TP
 .B set boldtext
 Use bold instead of reverse video for the title bar, status bar, key combos,
-line numbers, and selected text.  This can be overridden for the first four
-by setting the options \fBtitlecolor\fP, \fBstatuscolor\fP, \fBkeycolor\fP,
-and \fBnumbercolor\fP.
+function tags, line numbers, and selected text.  This can be overridden for
+the first five by setting the options \fBtitlecolor\fP, \fBstatuscolor\fP,
+\fBkeycolor\fP, \fBfunctioncolor\fP, and \fBnumbercolor\fP.
 .TP
 .B set brackets "\fIstring\fP"
 Set the characters treated as closing brackets when justifying