docs: mention the new 'set promptcolor' option

doc/nano.texi

@@ -956,6 +956,11 @@ Display a "scrollbar" on the righthand side of the edit window.
 It shows the position of the viewport in the buffer
 and how much of the buffer is covered by the viewport.
 
+@item set promptcolor [bold,][italic,]@var{fgcolor},@var{bgcolor}
+Use this color combination for the prompt bar.
+When this option is not specified, the colors of the title bar are used.
+@xref{@code{set functioncolor}} for valid color names.
+
 @item set punct "@var{characters}"
 Set the characters treated as closing punctuation when justifying
 paragraphs.  This may not include blank characters.  Only the

doc/nanorc.5

@@ -230,6 +230,11 @@ The cursor position is remembered for the 200 most-recently edited files.
 .B set preserve
 Preserve the XON and XOFF keys (\fB^Q\fR and \fB^S\fR).
 .TP
+.B set promptcolor \fR[\fBbold,\fR][\fBitalic,\fR]\fIfgcolor\fB,\fIbgcolor\fR
+Specify the color combination to use for the prompt bar.
+When this option is not specified, the colors of the title bar are used.
+See \fBset titlecolor\fR for more details.
+.TP
 .BI "set punct """ characters """
 Set the characters treated as closing punctuation when justifying
 paragraphs.  This may not include blank characters.  Only the

doc/sample.nanorc.in

@@ -203,6 +203,7 @@
 ## Paint the interface elements of nano.  These are examples;
 ## by default there are no colors, except for errorcolor.
 # set titlecolor bold,lightwhite,blue
+# set promptcolor lightwhite,lightblack
 # set statuscolor bold,lightwhite,green
 # set errorcolor bold,lightwhite,red
 # set selectedcolor lightwhite,magenta
@@ -214,6 +215,7 @@
 
 ## In root's .nanorc you might want to use:
 # set titlecolor bold,lightwhite,magenta
+# set promptcolor black,yellow
 # set statuscolor bold,lightwhite,magenta
 # set errorcolor bold,lightwhite,red
 # set selectedcolor lightwhite,cyan