[0.8 RELEASE CANDIDATE 2] Bugfix

This new RC fixes the following bugs:

• The firmware version reported via BLE was incorrect : #58
• Firmware freeze/crash when the button was pressed (to go to sleep) while a touch event was generated #60

A few typos were also fixed in the documentation (thanks to @Avamander)

During the analysis of #60, a potential bug was detected in the bootloader. An issue has been created to track it : lupyuen/pinetime-rust-mynewt#24

This version will be release as 0.8.1 in Master is no major bug are discovered.