make shower timer settings configurable

[lbbrhzn]

Is your feature request related to a problem? Please describe.
The settings for the shower timer are currently hardcoded. The max shower duration is fixed to 7 minutes.

Describe the solution you'd like
Make the max shower duration configurable through settings. Change the unit to seconds instead of ms.

Setting	Description
SHOWER_PAUSE_TIME	15 seconds, max time if water is switched off & on during a shower
SHOWER_MIN_DURATION	2 minutes, before recognizing its a shower
SHOWER_OFFSET_TIME	5 seconds grace time, to calibrate actual time under the shower
SHOWER_COLDSHOT_DURATION	10 seconds for cold water before turning back hot water
SHOWER_MAX_DURATION	7 minutes, before trigger a shot of cold water

Describe alternatives you've considered
Forking the repo and changing the hardcoded constants.
Using an automation in home assistant.

[proddy]

ok, wasn't sure if anyone actually used that feature! Do you just want the max duration (7 mins) to be configured?

[lbbrhzn]

yes! but adjusting the coldshot duration would also be nice.

[proddy]

added in b15