docs/esp8266/intro: Focus on hazards of unearthed power wrt electronics.

Author: pfalcon

docs/esp8266/tutorial/intro.rst

@@ -116,12 +116,11 @@ after it, here are troubleshooting recommendations:
  in general. If you experience issues with self-made or wall-wart style power
  supply, try USB power from a computer. Unearthed power supplies are also known
  to cause problems as they source of increased EMI (electromagnetic interference)
- - at the very least, as by the common safety standards they are considered
- a hazard which may lead to electrical device breakdown and eletric shock to
- humans. Please avoid using unearthed power connections at any time. In regard
- to FlashROM hardware problems, there are independent (not related to MicroPython
- in any way) reports
- `(e.g.) <https://github.com/peterhinch/micropython-samples.git>`_
+ - at the very least, and may lead to electrical devices breakdown. So, you are
+ advised to avoid using unearthed power connections when working with ESP8266
+ and other boards. In regard to FlashROM hardware problems, there are independent
+ (not related to MicroPython in any way) reports
+ `(e.g.) <http://internetofhomethings.com/homethings/?p=538>`_
  that on some ESP8266 modules, FlashROM can be programmed as little as 20 times
  before programming errors occur. This is *much* less than 100,000 programming
  cycles cited for FlashROM chips of a type used with ESP8266 by reputable