docs: put paths and filenames in italics, per 'man man-pages'

Plus a few other text and formatting tweaks.

doc/nano.1

@@ -318,8 +318,8 @@ See at the end of the \fB^G\fR help text for a complete list.
 .SH FILES
 \fBnano\fR will read two configuration files: first the system's
 \fInanorc\fR (if it exists), and then the user's \fInanorc\fR (if it
-exists), either \fB~/.nanorc\fR or \fI$XDG_CONFIG_HOME\fB/nano/nanorc\fR
-or \fB~/.config/nano/nanorc\fR, whichever is encountered first.  See
+exists), either \fI~/.nanorc\fR or \fI$XDG_CONFIG_HOME/nano/nanorc\fR
+or \fI~/.config/nano/nanorc\fR, whichever is encountered first.  See
 .BR nanorc (5)
 for more information on the possible contents of those files.
 
@@ -345,14 +345,14 @@ not by default distinguish modified from unmodified arrow keys.
 .sp
 Please report any other bugs that you encounter via:
 .br
-\fIhttps://savannah.gnu.org/bugs/?group=nano\fR.
+.IR https://savannah.gnu.org/bugs/?group=nano .
 .sp
 When nano crashes, it will save any modified buffers to emergency .save files.
 If you are able to reproduce the crash and you want to get a backtrace, define
 the environment variable \fBNANO_NOCATCH\fR.
 
 .SH HOMEPAGE
-\fIhttps://nano\-editor.org/\fR
+.I https://nano\-editor.org/
 
 .SH SEE ALSO
 .BR nanorc (5)

doc/nanorc.5

@@ -34,10 +34,10 @@ If you want the old, Pico behavior back, you can use \fBset breaklonglines\fR,
 The \fInanorc\fP file contains the default settings for \fBnano\fP, a
 small and friendly editor.  The file should be in Unix format, not in
 DOS or Mac format.  During startup, \fBnano\fP will first read the
-system-wide settings, from \fB/etc/nanorc\fP (the exact path might be
+system-wide settings, from \fI/etc/nanorc\fP (the exact path might be
 different on your system), and then the user-specific settings, either
-from \fB~/.nanorc\fR or from \fI$XDG_CONFIG_HOME\fB/nano/nanorc\fR
-or from \fB~/.config/nano/nanorc\fR, whichever is encountered first.
+from \fI~/.nanorc\fR or from \fI$XDG_CONFIG_HOME/nano/nanorc\fR
+or from \fI~/.config/nano/nanorc\fR, whichever is encountered first.
 
 .SH OPTIONS
 The configuration file accepts a series of \fBset\fP and \fBunset\fP
@@ -873,10 +873,10 @@ for \fBunbind\fR it means all menus where the specified \fIkey\fR exists.
 
 .SH FILES
 .TP
-.B /etc/nanorc
+.I /etc/nanorc
 System-wide configuration file.
 .TP
-.BR ~/.nanorc " or " \fI$XDG_CONFIG_HOME\fB/nano/nanorc " or " ~/.config/nano/nanorc
+.IR ~/.nanorc " or " $XDG_CONFIG_HOME/nano/nanorc " or " ~/.config/nano/nanorc
 Per-user configuration file.
 
 .SH SEE ALSO

doc/rnano.1

@@ -45,15 +45,16 @@ not make backup files nor do spell checking.
 .SH OPTIONS
 .TP
 .BR \-h ", " \-\-help
-Show a summary of command-line options and exit.
+Show the available command-line options and exit.
 .PP
-See the \fBnano\fP(1) manpage for all available options.
+For all existing options, see the \fBnano\fR(1) man page.
 
 .SH BUGS
-Please report bugs via \fIhttps://savannah.gnu.org/bugs/?group=nano\fR.
+Please report bugs via
+.IR https://savannah.gnu.org/bugs/?group=nano .
 
 .SH HOMEPAGE
-https://nano-editor.org/
+.I https://nano-editor.org/
 
 .SH SEE ALSO
 .BR nano (1)