Demonstrate Help Menu in README

Author: Jack Desert

README.rst

@@ -50,6 +50,40 @@ Features
 [2] If the terminal supports it (most terminals do), this allows pasting
 without going into paste mode. It will keep the indentation.
 
+Command Line Options
+********************
+
+The help menu shows basic command-line options.
+
+::
+
+    $ ptpython --help
+    usage: ptpython [-h] [--vi] [-i] [--light-bg] [--dark-bg] [--config-file CONFIG_FILE]
+                    [--history-file HISTORY_FILE] [-V]
+                    [args ...]
+
+    ptpython: Interactive Python shell.
+
+    positional arguments:
+      args                  Script and arguments
+
+    optional arguments:
+      -h, --help            show this help message and exit
+      --vi                  Enable Vi key bindings
+      -i, --interactive     Start interactive shell after executing this file.
+      --light-bg            Run on a light background (use dark colors for text).
+      --dark-bg             Run on a dark background (use light colors for text).
+      --config-file CONFIG_FILE
+                            Location of configuration file.
+      --history-file HISTORY_FILE
+                            Location of history file.
+      -V, --version         show program's version number and exit
+
+    environment variables:
+      PTPYTHON_CONFIG_HOME: a configuration directory to use
+      PYTHONSTARTUP: file executed on interactive startup (no default)
+
+
 __pt_repr__: A nicer repr with colors
 *************************************
 
@@ -211,7 +245,7 @@ FAQ
 
 **Q**: The ``Meta``-key doesn't work.
 
-**A**: For some terminals you have to enable the Alt-key to act as meta key, but you 
+**A**: For some terminals you have to enable the Alt-key to act as meta key, but you
 can also type ``Escape`` before any key instead.