Add missing public classes and functions to API documentation

- Fix docstring underline mismatch error

Fixes #631.
Might depend on #636?

docs/api.rst

@@ -7,8 +7,38 @@ icalendar.cal
 .. automodule:: icalendar.cal
    :members:
 
+icalendar.caselessdict
+++++++++++++++++++++++
+
+.. automodule:: icalendar.caselessdict
+   :members:
+
+icalendar.cli
++++++++++++++
+
+.. automodule:: icalendar.cli
+   :members:
+
+icalendar.parser
+++++++++++++++++
+
+.. automodule:: icalendar.parser
+   :members:
+
+icalendar.parser_tools
+++++++++++++++++++++++
+
+.. automodule:: icalendar.parser_tools
+   :members:
+
 icalendar.prop
 ++++++++++++++
 
 .. automodule:: icalendar.prop
    :members:
+
+icalendar.tools
++++++++++++++++
+
+.. automodule:: icalendar.tools
+   :members:

src/icalendar/prop.py

@@ -2,6 +2,7 @@
 prefer) for the classes/datatypes that are used in iCalendar:
 
 ###########################################################################
+
 # This module defines these property value data types and property parameters
 
 4.2 Defined property parameters are: