Document command line options.

docs/language/cli.rst

@@ -0,0 +1,35 @@
+======================
+Command Line Interface
+======================
+
+Command line options
+--------------------
+
+.. cmdoption:: -c <command>
+
+   Execute the Hy code in *command*.
+
+   .. code-block:: bash
+
+      $ hy -c "(print (+ 2 2))"
+      4
+
+.. cmdoption:: -i <command>
+
+   Execute the Hy code in *command*, then stay in REPL.
+
+.. cmdoption:: --spy
+
+   Print equivalent Hy code before executing. For example::
+
+    => (defn salutationsnm [name] (print (+ "Hy " name "!")))
+    def salutationsnm(name):
+        return print(((u'Hy ' + name) + u'!'))
+    => (salutationsnm "YourName")
+    salutationsnm(u'YourName')
+    Hy YourName!
+    =>
+
+.. cmdoption:: -v
+
+   Print the Hy version number and exit.

docs/language/index.rst

@@ -7,6 +7,7 @@ Contents:
 .. toctree::
    :maxdepth: 3
 
+   cli
    api
    core
    internals