Adapt doorlock documentation to current realities:
- wire the solenoid lock a little differently (to make sure it doesn't
  conflict with the keypad)
- mention that some breadboards don't label holes the same way the
  reference breadboard does
- keypad is no longer TBD
- user instructions

Signed-off-by: Bernhard Rosenkränzer <bernhard.rosenkraenzer.ext@huawei.com>