Add missing modules to API docs build.

Includes tweaks to Sphinx config and module files to help the docs build.

Reviewed the docs build with:
sphinx-build -E -W -b html . _build/html

diff --git a/README.rst b/README.rst
index 3522ed49121f490aa843abe8a9a7585b2e1e9813..60f78b3ecc963a012aea042ce8a11401e0bb35f7 100755 (executable)
--- a/README.rst
+++ b/README.rst
@@ -26,8 +26,10 @@ on hosts running micropython. Working code exists to emulate the CircuitPython p
 * **digitalio** - digital input/output pins, using pin identities from board+microcontroller packages
 * **bitbangio** - software-driven interfaces for I2C, SPI
 * **busio** - hardware-driven interfaces for I2C, SPI, UART
-* **time** * - substitute functions monkey-patched to time module
+* **pulseio** - contains classes that provide access to basic pulse IO (PWM)
 
+For details, see the `Blinka API reference
+<https://circuitpython.readthedocs.io/projects/blinka/en/latest/index.html>`_.
 
 Dependencies
 =============