doc: improve man page (mostly fonts)
Problems reported by Helge Kreutzmann in:
https://lists.gnu.org/r/bug-bison/2026-01/msg00000.html
* doc/bison.x: Refontify, mostly.
* src/getargs.c (usage): Clarify usage message.
diff --git a/doc/bison.x b/doc/bison.x
index edaebe8..cb4f7a8 100644
--- a/doc/bison.x
+++ b/doc/bison.x
@@ -2,48 +2,49 @@
bison \- GNU Project parser generator (yacc replacement)
[description]
-.I Bison
-is a parser generator in the style of
-.IR yacc (1).
-It should be upwardly compatible with input files designed
-for
-.IR yacc .
+The
+.B bison
+parser generator inputs grammars in the style of
+.BR yacc (1)
+and outputs parsers for those grammers.
.PP
Input files should follow the
-.I yacc
+.B yacc
convention of ending in
-.BR .y .
+.IR .y .
Unlike
-.IR yacc ,
+.BR yacc ,
the generated files do not have fixed names, but instead use the prefix
of the input file.
-Moreover, if you need to put
-.I C++
-code in the input file, you can end his name by a C++-like extension
-(.ypp or .y++), then bison will follow your extension to name the
-output file (.cpp or .c++).
+Moreover, if you need to put C++
+code in the input file, you can end its name by a C++-like extension
+.RI ( .ypp
+or
+.IR .y++ ),
+and then
+.B bison
+will follow your extension to name the
+output file
+.RI ( .cpp
+or
+.IR .c++ ).
For instance, a grammar description file named
-.B parse.yxx
+.I parse.yxx
would produce the generated parser in a file named
-.BR parse.tab.cxx ,
+.IR parse.tab.cxx ,
instead of
-.IR yacc 's
-.B y.tab.c
-or old
-.I Bison
-version's
-.BR parse.tab.c .
+.BR yacc 's
+.IR y.tab.c .
.PP
This description of the options that can be given to
-.I bison
+.B bison
is adapted from the node
.B Invocation
-in the
-.B bison.texi
-manual, which should be taken as authoritative.
+in the Bison manual, which should be taken as authoritative.
.PP
-.I Bison
-supports both traditional single-letter options and mnemonic long
+The
+.B bison
+command supports both traditional single-letter options and mnemonic long
option names. Long option names are indicated with
.B \-\-
instead of
diff --git a/src/getargs.c b/src/getargs.c
index 79a8b70..9e53d3f 100644
--- a/src/getargs.c
+++ b/src/getargs.c
@@ -422,12 +422,12 @@
Tuning the Parser:\n\
-L, --language=LANGUAGE specify the output programming language\n\
-S, --skeleton=FILE specify the skeleton to use\n\
- -t, --debug instrument the parser for tracing\n\
+ -t, --debug instrument the parser for tracing;\n\
same as '-Dparse.trace'\n\
--locations enable location support\n\
-D, --define=NAME[=VALUE] similar to '%define NAME VALUE'\n\
-F, --force-define=NAME[=VALUE] override '%define NAME VALUE'\n\
- -p, --name-prefix=PREFIX prepend PREFIX to the external symbols\n\
+ -p, --name-prefix=PREFIX prepend PREFIX to the external symbols;\n\
deprecated by '-Dapi.prefix={PREFIX}'\n\
-l, --no-lines don't generate '#line' directives\n\
-k, --token-table include a table of token names\n\
@@ -443,7 +443,7 @@
--report-file=FILE write report to FILE\n\
-v, --verbose same as '--report=state'\n\
-b, --file-prefix=PREFIX specify a PREFIX for output files\n\
- -o, --output=FILE leave output to FILE\n\
+ -o, --output=FILE output to FILE\n\
-g, --graph[=FILE] also output a graph of the automaton\n\
--html[=FILE] also output an HTML report of the automaton\n\
-x, --xml[=FILE] also output an XML report of the automaton\n\
