Add door-open-chime.yaml and add option to set alarm output shared as false

[SteeledKnight]

door-open-chime.yaml: Add a package that creates a virtual button that on press pulses on the selected output (usually connected to a piezo buzzer). This would typically be used as a chime to alert when a door has been opened.

alarm_shared: Adding a substitution to enable or disable whether the alarm output is shared. See issue https://github.com/konnected-io/konnected-esphome/issues/27. Default is set to true to follow the current standard.