fix printing of fractionals (not scientific anymore), added -p flag

rpn.pod

@@ -7,13 +7,15 @@ rpn - Programmable command-line calculator using reverse polish notation
     Usage: rpn [-bdvh] [<operator>]
     
     Options:
-      -b, --batchmode     enable batch mode
-      -d, --debug         enable debug mode
-      -s, --stack         show last 5 items of the stack (off by default)
-      -i  --intermediate  print intermediate results
-      -m, --manual        show manual
-      -v, --version       show version
-      -h, --help          show help
+      -b, --batchmode       enable batch mode
+      -d, --debug           enable debug mode
+      -s, --stack           show last 5 items of the stack (off by default)
+      -i  --intermediate    print intermediate results
+      -m, --manual          show manual
+      -c, --config <file>   load <file> containing LUA code
+      -p, --precision <int> floating point number precision (default 2)
+      -v, --version         show version
+      -h, --help            show help
     
     When <operator>  is given, batch  mode ist automatically  enabled. Use
     this only when working with stdin. E.g.: echo "2 3 4 5" | rpn +
@@ -342,6 +344,16 @@ B<Please note, that io, networking and system stuff is not allowed
 though. So you can't open files, execute other programs or open a
 connection to the outside!>
 
+=head1 CONFIGURATION
+
+B<rpn> can be configured via command line flags (see usage
+above). Most of the flags are also available as interactive commands,
+such as C<--batch> has the same effect as the B<batch> command.
+
+The floating point number  precision option C<-p, --precision> however
+is not available as interactive command,  it MUST be configured on the
+command line, if needed. The default precision is 2.
+
 =head1 GETTING HELP
 
 In interactive mode you can enter the B<help> command (or B<?>) to get
@@ -364,7 +376,7 @@ L<https://github.com/TLINDEN/rpnc/issues>.
 
 This software is licensed under the GNU GENERAL PUBLIC LICENSE version 3.
 
-Copyright (c) 2023 by Thomas von Dein
+Copyright (c) 2023-2024 by Thomas von Dein
 
 This software uses the following GO modules: