Update how-to-build.rst

Documentation/how-to-build.rst

@@ -71,8 +71,20 @@ Dependencies
         brew install ninja
         pip3 install --user meson  # see https://mesonbuild.com/Getting-meson.html - you will have to add ~/.local/bin to your PATH.
 
-* **python3-crc16**: Install with ``pip3 install --user crc16``.
-* **python3-pillow**: Python Image Library ``pip3 install --user pillow``.
+* One of three CRC packages are required. Pick one:
+
+        .. code-block:: shell-session
+            pip3 install --user crc16
+            
+        .. code-block:: shell-session
+            pip3 install --user crcmod
+            
+        .. code-block:: shell-session
+            pip3 install --user crcmod
+        
+* **python3-pillow**: Python Image Library
+       .. code-block:: shell-session
+            pip3 install --user pillow
         
   - Arch