Recovered MAC address docs from previous driver code

src/uninitialized_device.rs

@@ -31,6 +31,22 @@ impl<SpiBus: ActiveBus> UninitializedDevice<SpiBus> {
         UninitializedDevice { bus }
     }
 
+    /// Initialize the device with a MAC address and mode settings.
+    ///
+    /// Consider using freely available private/locally administered mac
+    /// addresses that match the following hex pattern:
+    ///
+    /// ```code
+    ///  x2-xx-xx-xx-xx-xx
+    ///  x6-xx-xx-xx-xx-xx
+    ///  xA-xx-xx-xx-xx-xx
+    ///  xE-xx-xx-xx-xx-xx
+    /// ```
+    ///
+    /// "Universally administered and locally administered addresses are
+    /// distinguished by setting the second-least-significant bit of the first
+    /// octet of the address"
+    /// [Wikipedia](https://en.wikipedia.org/wiki/MAC_address#Universal_vs._local)
     pub fn initialize(
         self,
         mac: MacAddress,