Document --force-stdin-eval-mode opt

Impl: rakudo/rakudo@9ce896d8bf
      Raku/nqp@c38cfe87f5

Author: zoffixznet

doc/Programs/00-running.pod6

@@ -11,7 +11,9 @@
 
 =head1 DESCRIPTION
 
-With no arguments, enters a REPL. With a C<[programfile]> or the C<-e>
+With no arguments, enters a REPL on TTY displays or evals STDIN on non-TTY
+(see C<--force-stdin-eval-mode> argument to force one of these behaviors).
+With a C<[programfile]> or the C<-e>
 option, compiles the given program and, by default, also executes the
 compiled code.
 
@@ -46,6 +48,12 @@ compiled code.
                             any other extension outputs in HTML
   --doc=module         use Pod::To::[module] to render inline documentation
 
+  --force-stdin-eval-mode=interactive|non-interactive
+                       when running without -e or filename arguments,
+                       do not rely on whether STDIN is a TTY and force the
+                       eval of code from STDIN to be via REPL (interactive)
+                       or without REPL (non-interactive)
+
 =end code
 
 Note that only boolean single-letter options may be bundled.