hru.1: fixes formatting

docs/hru.1

@@ -25,23 +25,30 @@ value is greater than one.
 .SH DIAGNOSTICS
 
 If encountering non-integer characters in the standard input, the program will
-exit with the appropriate error code as defined by sysexits.h(3) and print an
+exit with the appropriate error code as defined by
-error message.
+.BR sysexits.h (3)
+and print an error message.
 .\"
 .SH RATIONALE
 
-The GNU project\(cqs ls(1) implementation contains a human-readable option (-h)
+The GNU project\(cqs
-that, when specified, makes the tool print size information in a format more
+.BR ls (1)
-immediately readable. This functionality is useful not only in the context of
+implementation contains a human-readable option (\fB-h\fP) that, when specified,
-ls(1) so the decision was made to split it into a new tool. The original
+makes the tool print size information in a format more immediately readable.
-functionality in GNU\(cqs ls(1) can be emulated with fop(1) combined with this
+This functionality is useful not only in the context of
-program.
+.BR ls (1)
+so the decision was made to split it into a new tool. The original functionality
+in GNU\(cqs
+.BR ls (1)
+can be emulated with
+.BR fop (1)
+combined with this program.
 .\"
 .SH STANDARDS
 
 The standard unit prefixes as specified by the Bureau International des Poids
-et Mesures (BIPM) in the ninth edition of The International System of Units
+et Mesures (BIPM) in the ninth edition of The International System of Units (SI)
-(SI) are utilized for the ouput of conversions.
+are utilized for the ouput of conversions.
 .\"
 .SH AUTHOR