HomeKit instructions are not correct

[palazzem]

Describe the bug
HomeKit docs are not correct and the current configuration creates multiple instances. We should update it to:

homekit:
  - filter:
      include_domains:
        - alarm_control_panel
    entity_config:
      alarm_control_panel.alarm_panel:
       code: <PIN CODE>
    name: HASS Bridge Alarm  # Remove the YAML list block (`-`)
    port: 21065

Error message
No errors, but multiple instances are created in HomeKit and the filter is ignored.

Expected behavior
Having only one working instance.

Additional context
n/a

To Reproduce
n/a

Environment

• Operating System (OS):
• Library version (commit or version number):
• Home Assistant version:
• Last working Home Assistant release (if known):

[palazzem]

We should also update this section:

    entity_config:
      alarm_control_panel.<YOUR_ALARM_PANEL_ENTITY_ID>:
       code: <PIN CODE>

[palazzem]

Closed with #142