readme improvements
readme improvements

iriark01/yotta,autopulated/yotta,BlackstoneEngineering/yotta,eyeye/yotta,ntoll/yotta,bridadan/yotta,stevenewey/yotta,ARMmbed/yotta,autopulated/yotta,stevenewey/yotta,BlackstoneEngineering/yotta,iriark01/yotta,theotherjimmy/yotta,eyeye/yotta,ARMmbed/yotta,ntoll/yotta,theotherjimmy/yotta,bridadan/yotta