docs: explain the effect of --minibar / -_ / 'set minibar'

Also, colorize 'set minibar' as valid option in a nanorc file.

doc/nano.1

@@ -337,6 +337,20 @@ and \fBS\fR when soft-wrapping.
 When the buffer is modified, a star (\fB*\fR) is shown after the
 filename in the center of the title bar.
 .TP
+.BR \-_ ", " \-\-minibar
+Suppress the title bar and instead show information about
+the current buffer at the bottom of the screen, in the space
+for the status bar.  In this "minibar" the file name is shown
+on the left, followed by an asterisk if the buffer has been modified.
+On the right are displayed the current line and column number, the
+code of the character under the cursor (in Unicode format: U+xxxx),
+the same flags as are shown by \fB\-\-stateflags\fR, and a percentage
+that expresses how far the cursor is into the file (linewise).
+When a file is loaded or saved, and also when switching between buffers,
+the number of lines in the buffer is displayed after the file name.
+This number is cleared upon the next keystroke, or replaced with an
+[i/n] counter when multiple buffers are open.
+.TP
 .BR \-! ", " \-\-magic
 When neither the file's name nor its first line give a clue,
 try using libmagic to determine the applicable syntax.

doc/nano.texi

@@ -477,6 +477,21 @@ and @code{S} when soft-wrapping.
 When the buffer is modified, a star (@code{*}) is shown after the
 filename in the center of the title bar.
 
+@item -_
+@itemx --minibar
+Suppress the title bar and instead show information about
+the current buffer at the bottom of the screen, in the space
+for the status bar.  In this "minibar" the file name is shown
+on the left, followed by an asterisk if the buffer has been modified.
+On the right are displayed the current line and column number, the
+code of the character under the cursor (in Unicode format: U+xxxx),
+the same flags as are shown by @code{--stateflags}, and a percentage
+that expresses how far the cursor is into the file (linewise).
+When a file is loaded or saved, and also when switching between buffers,
+the number of lines in the buffer is displayed after the file name.
+This number is cleared upon the next keystroke, or replaced with an
+[i/n] counter when multiple buffers are open.
+
 @item -!
 @itemx --magic
 When neither the file's name nor its first line give a clue,
@@ -911,6 +926,20 @@ searches.  This may not include blank characters.  The opening set must
 come before the closing set, and the two sets must be in the same order.
 The default value is "@t{(<[@{)>]@}}".
 
+@item set minibar
+Suppress the title bar and instead show information about
+the current buffer at the bottom of the screen, in the space
+for the status bar.  In this "minibar" the file name is shown
+on the left, followed by an asterisk if the buffer has been modified.
+On the right are displayed the current line and column number, the
+code of the character under the cursor (in Unicode format: U+xxxx),
+the same flags as are shown by @code{set stateflags}, and a percentage
+that expresses how far the cursor is into the file (linewise).
+When a file is loaded or saved, and also when switching between buffers,
+the number of lines in the buffer is displayed after the file name.
+This number is cleared upon the next keystroke, or replaced with an
+[i/n] counter when multiple buffers are open.
+
 @item set morespace
 Deprecated option since it has become the default setting.
 When needed, use @code{unset emptyline} instead.

doc/nanorc.5

@@ -182,6 +182,20 @@ searches.  This may not include blank characters.  The opening set must
 come before the closing set, and the two sets must be in the same order.
 The default value is "\fB(<[{)>]}\fP".
 .TP
+.B set minibar
+Suppress the title bar and instead show information about
+the current buffer at the bottom of the screen, in the space
+for the status bar.  In this "minibar" the file name is shown
+on the left, followed by an asterisk if the buffer has been modified.
+On the right are displayed the current line and column number, the
+code of the character under the cursor (in Unicode format: U+xxxx),
+the same flags as are shown by \fBset stateflags\fR, and a percentage
+that expresses how far the cursor is into the file (linewise).
+When a file is loaded or saved, and also when switching between buffers,
+the number of lines in the buffer is displayed after the file name.
+This number is cleared upon the next keystroke, or replaced with an
+[i/n] counter when multiple buffers are open.
+.TP
 .B set morespace
 Deprecated option since it has become the default setting.
 When needed, use \fBunset emptyline\fR instead.

doc/sample.nanorc.in

@@ -84,6 +84,9 @@
 ## come before the latter set, and both must be in the same order.
 # set matchbrackets "(<[{)>]}"
 
+## Suppress title bar and show file name and editor state at the bottom.
+# set minibar
+
 ## Enable mouse support, if available for your system.  When enabled,
 ## mouse clicks can be used to place the cursor, set the mark (with a
 ## double click), and execute shortcuts.  The mouse will work in the X

syntax/nanorc.nanorc

@@ -7,7 +7,7 @@ comment "#"
 color brightred ".*"
 
 # Keywords
-color brightgreen "^[[:space:]]*(set|unset)[[:space:]]+(afterends|allow_insecure_backup|atblanks|autoindent|backup|boldtext|breaklonglines|casesensitive|constantshow|cutfromcursor|emptyline|historylog|indicator|jumpyscrolling|linenumbers|locking|magic|mouse|multibuffer|noconvert|nohelp|nonewlines|positionlog|preserve|quickblank|rawsequences|rebinddelete|regexp|saveonexit|showcursor|smarthome|softwrap|stateflags|suspendable|tabstospaces|trimblanks|unix|wordbounds|zap)\>"
+color brightgreen "^[[:space:]]*(set|unset)[[:space:]]+(afterends|allow_insecure_backup|atblanks|autoindent|backup|boldtext|breaklonglines|casesensitive|constantshow|cutfromcursor|emptyline|historylog|indicator|jumpyscrolling|linenumbers|locking|magic|minibar|mouse|multibuffer|noconvert|nohelp|nonewlines|positionlog|preserve|quickblank|rawsequences|rebinddelete|regexp|saveonexit|showcursor|smarthome|softwrap|stateflags|suspendable|tabstospaces|trimblanks|unix|wordbounds|zap)\>"
 color yellow "^[[:space:]]*set[[:space:]]+((error|function|key|number|prompt|scroller|selected|status|stripe|title)color)[[:space:]]+(bold,)?(italic,)?(bright|light)?(white|black|red|blue|green|yellow|magenta|cyan|normal|pink|purple|mauve|lagoon|mint|lime|peach|orange|latte)?(,(light)?(white|black|red|blue|green|yellow|magenta|cyan|normal|pink|purple|mauve|lagoon|mint|lime|peach|orange|latte))?\>"
 color brightgreen "^[[:space:]]*set[[:space:]]+(backupdir|brackets|errorcolor|functioncolor|keycolor|matchbrackets|numbercolor|operatingdir|promptcolor|punct|quotestr|scrollercolor|selectedcolor|speller|statuscolor|stripecolor|titlecolor|whitespace|wordchars)[[:space:]]+"
 color brightgreen "^[[:space:]]*set[[:space:]]+(fill[[:space:]]+-?[[:digit:]]+|(guidestripe|tabsize)[[:space:]]+[1-9][0-9]*)\>"