Changes
/* Introduction to fitlet3 */
* [https://fit-iot.com/files/fitlet3/documents/fitlet3-owners-manual.pdf fitlet3 owner's manual]
-->
* [https://fit-iot.com/files/fitlet3/documents/fitlet3_datasheet_rev+1_0fitlet3_datasheet.pdf fitlet3 Datasheet]
=== Hardware ===
