tweaks: consistently use .sp instead of .PP to insert a blank line

And use plain .P to start a new paragraph.

doc/nano.1

@@ -57,18 +57,18 @@ Consecutive \fB^K\fRs will put all deleted lines together in the cutbuffer.
 Any cursor movement or executing any other command will cause the next
 \fB^K\fR to overwrite the cutbuffer.  A \fB^U\fR will paste the current
 contents of the cutbuffer at the current cursor position.
-.PP
+.sp
 When a more precise piece of text needs to be cut or copied, one can mark
 its start with \fB^6\fR, move the cursor to its end (the marked text will be
 highlighted), and then use \fB^K\fR to cut it, or \fBM\-6\fR to copy it to the
 cutbuffer.  One can also save the marked text to a file with \fB^O\fR, or
 spell check it with \fB^T\fR.
-.PP
+.sp
 On some terminals, text can be selected also by holding down Shift while
 using the arrow keys.  Holding down the Ctrl or Alt key too will increase
 the stride.
 Any cursor movement without Shift being held will cancel such a selection.
-.PP
+.sp
 The two lines at the bottom of the screen show some important commands;
 the built-in help (\fB^G\fR) lists all the available ones.
 The default key bindings can be changed via a \fInanorc\fR file -- see
@@ -356,5 +356,5 @@ the environment variable \fBNANO_NOCATCH\fR.
 
 .SH SEE ALSO
 .BR nanorc (5)
-.PP
+.sp
 \fI/usr/share/doc/nano/\fP (or equivalent on your system)

doc/nanorc.5

@@ -45,20 +45,20 @@ commands, which can be used to configure nano on startup without using
 command-line options.  Additionally, there are some commands to define
 syntax highlighting and to rebind keys -- see the two separate sections
 on those.  \fBnano\fP reads one command per line.
-.PP
+.sp
 Options in \fInanorc\fP files take precedence over nano's defaults, and
 command-line options override \fInanorc\fP settings.  Also, options that
 do not take an argument are unset by default.  So using the \fBunset\fR
 command is only needed when wanting to override a setting of the system's
 \fInanorc\fR file in your own \fInanorc\fR.  Options that take an
 argument cannot be unset.
-.PP
+.sp
 Below, the \fIstring\fR parameters need to be enclosed in double quotes.
 Quotes inside these string parameters don't have to be escaped with
 backslashes.  The last double quote in the string will be treated as its
 end.  For example, for the \fBbrackets\fP option, "\fB"')>]}\fP" will
 match \fB"\fP, \fB'\fP, \fB)\fP, \fB>\fP, \fB]\fP, and \fB}\fP.
-.PP
+.sp
 The supported commands and arguments are:
 
 .TP 3
@@ -434,14 +434,14 @@ a more general mechanism: the filtering of buffer or marked text through
 an external command.  Such filtering is done by typing \fB^R^X\fR and then
 preceding your formatter command with the pipe symbol (\fB|\fR).  It has
 the added advantage that the operation can be undone.
-.PP
+.sp
 If you use such a formatting command regularly, you could assign the relevant
 series of keystrokes to a single key in your nanorc:
-.PP
+.sp
 .RS
 .B "bind  M\-F  \(dq^R^X|yourformatcommand^M\(dq  main"
 .RE
-.PP
+.sp
 (Note that the \fB^R\fR, \fB^X\fR, and \fB^M\fR are each a single, literal
 control character.  You can enter them by preceding each with \fBM\-V\fR.)
 

doc/rnano.1

@@ -29,7 +29,7 @@ rnano \- a restricted nano
 \fBrnano\fR runs the \fBnano\fR editor in restricted mode.  This allows
 editing only the specified file or files, and doesn't allow the user
 access to the filesystem nor to a command shell.
-.PP
+.sp
 In restricted mode, \fBnano\fR will:
 .IP \[bu] 2
 not allow suspending;
@@ -46,7 +46,7 @@ not make backup files nor do spell checking.
 .TP
 .BR \-h ", " \-\-help
 Show the available command-line options and exit.
-.PP
+.P
 For all existing options, see the \fBnano\fR(1) man page.
 
 .SH BUGS