Adding scrolling_label.py and example to documentation

Author: rgrizzell

docs/api.rst

@@ -13,3 +13,6 @@
 
 .. automodule:: adafruit_display_text.bitmap_label
    :members:
+
+.. automodule:: adafruit_display_text.scrolling_label
+   :members:

docs/examples.rst

@@ -1,4 +1,4 @@
-Simple test
+Simple Test
 ------------
 
 Ensure your device works with this simple test.
@@ -7,7 +7,7 @@ Ensure your device works with this simple test.
     :caption: examples/display_text_simpletest.py
     :linenos:
 
-Bitmap_label Simple test
+Bitmap_label Simple Test
 ------------------------
 
 Simple test using bitmap_label to display text
@@ -16,6 +16,15 @@ Simple test using bitmap_label to display text
     :caption: examples/display_text_bitmap_label_simpletest.py
     :linenos:
 
+ScrollingLabel Simple Test
+---------------------------
+
+Simple test using scrolling_label to display text
+
+.. literalinclude:: ../examples/display_text_scrolling_label.py
+    :caption: examples/display_text_scrolling_label.py
+    :linenos:
+
 Label vs Bitmap_label Comparison
 --------------------------------
 
@@ -25,7 +34,7 @@ Example to compare Label and Bitmap_Label characteristics
     :caption: examples/display_text_label_vs_bitmap_label_comparison.py
     :linenos:
 
-Background color example
+Background Color Example
 ------------------------
 
 Show the text backgrounds features
@@ -34,7 +43,7 @@ Show the text backgrounds features
     :caption: examples/display_text_background_color.py
     :linenos:
 
-Text padding example
+Text Padding Example
 --------------------
 
 Show the text padding features in all directions
@@ -61,7 +70,7 @@ Boundingbox demonstration
     :caption: examples/display_text_textarea_boundingbox.py
     :linenos:
 
-Align Baseline example
+Align Baseline Example
 ----------------------
 
 Demonstrate how to align different labels to a common horizontal line
@@ -70,7 +79,7 @@ Demonstrate how to align different labels to a common horizontal line
     :caption: examples/display_text_label_align_baseline_comparison.py
     :linenos:
 
-Magtag example
+Magtag Example
 --------------
 
 Uses the MAGTAG to display some text
@@ -79,7 +88,7 @@ Uses the MAGTAG to display some text
     :caption: examples/display_text_magtag.py
     :linenos:
 
-MatrixPortal example
+MatrixPortal Example
 --------------------
 
 Uses the MatrixPortal to display some text
@@ -88,7 +97,7 @@ Uses the MatrixPortal to display some text
     :caption: examples/display_text_matrixportal.py
     :linenos:
 
-PyPortal example
+PyPortal Example
 ----------------
 
 Uses the Pyportal to display some text
@@ -97,7 +106,7 @@ Uses the Pyportal to display some text
     :caption: examples/display_text_pyportal.py
     :linenos:
 
-Wraptest example
+Wraptest Example
 ----------------
 
 Illustrates the wraptest feature