Add images for bitmap and QR code.

README.md

@@ -2522,10 +2522,14 @@ different callback if the application required it.
 ```python
 from gui.widgets import BitMap
 ```
+![Image](./images/bitmap.JPG)  
 
 This renders a monochrome bitmap stored in a file to a rectangular region. The
 bitmap file format is C source code generated by the Linux `bitmap` editor. The
 bitmap may be rendered in any color. Data and colors can be changed at run time.
+The widget is intended for larger bitmaps and is designed to minimise RAM usage
+at cost of performance. For fast updates of smaller bitmaps consider using an
+[icon font](https://github.com/peterhinch/micropython-font-to-py/tree/master/icon_fonts).
 
 Constructor mandatory positional args:  
  1. `writer` A `Writer` instance.
@@ -2546,10 +2550,9 @@ Methods:__
  * `color` args `fgcolor=None`, `bgcolor=None`. Causes the image colors to be
  changed. The file will be re-read and the image updated.
 
-The widget is designed to minimise RAM usage at cost of performance. This is
-because images may be large. When an update occurs there will be a brief "dead
-time" when the GUI is unresponsive. This is not noticeable if the image is
-displayed when a screen initialises, or if it changes in response to a user
+Beacuse of the use of file storage when an update occurs there will be a brief
+"dead time" when the GUI is unresponsive. This is not noticeable if the image
+is displayed when a screen initialises, or if it changes in response to a user
 action. Use in animations is questionable.
 
 See `gui/demos/bitmap.py` for a usage example.
@@ -2561,6 +2564,7 @@ See `gui/demos/bitmap.py` for a usage example.
 ```python
 from gui.widgets import QRMap
 ```
+![Image](./images/qrcode.JPG)  
 
 This renders QR codes generated using the [uQR](https://github.com/JASchilz/uQR)
 application. Images may be scaled to render them at larger sizes. Please see