examples/misc/01-power/README.txt: fixed wording.

Author: icculus

examples/misc/01-power/README.txt

@@ -1,4 +1,4 @@
 This example code reports power status (plugged in, battery level, etc).
 
 Note that only Chrome-based browsers support this API currently. Firefox and
-Safari will report this as unsupported, but this may change later!
+Safari will report this as unknown, but this may change later!