docs: Add documentation for new service and power features

Signed-off-by:  Eric Callahan <arksine.code@gmail.com>

docs/configuration.md

@@ -213,6 +213,13 @@ restart_klipper_when_powered: False
 #   If set to True, Moonraker will issue a "FIRMWARE_RESTART" to Klipper
 #   after the device has been powered on.  The default is False, thus no
 #   attempt to made to restart Klipper after power on.
+bound_service:
+#   Can be set to any service Moonraker is authorized to manage with the
+#   exception of the moonraker service itself. See the tip below this section
+#   for details on what services are authorized.  When a bound service has
+#   been set the service will be started when the device powers on and stopped
+#   when the device powers off.  The default is no service is bound to the
+#   device.
 restart_delay: 1.
 #   If "restart_klipper_when_powered" is set, this option specifies the amount
 #   of time (in seconds) to delay the restart.  Default is 1 second.
@@ -310,8 +317,21 @@ off_code:
 #   The above options are used for "rf" devices.  The
 #   codes should be valid binary codes that are send via the RF transmitter.
 #   For example: 1011.
-
 ```
+
+!!! Tip
+    Moonraker is authorized to manage the `klipper`, `klipper_mcu`,
+    `webcamd`, `MoonCord`, `KlipperScreen`, and `moonraker-telegram-bot`
+    services.  It can also manage multiple instances of a service, ie:
+    `klipper_1`, `klipper_2`.  Keep in mind that service names are case
+    sensitive.
+
+!!! Note
+    If a device has been bound to the `klipper` service and the
+    `restart_klipper_when_powered` option is set to `True`, the restart
+    will be scheduled to execute after Klipper reports that its startup
+    sequence is complete.
+
 Below are some potential examples:
 ```ini
 # moonraker.conf

docs/web_api.md

@@ -833,27 +833,26 @@ Returns: Information about the host system in the following format:
 ```json
 {
     "system_info": {
-        "available_services": ["moonraker", "klipper"],
         "cpu_info": {
-            "cpu_count": 1,
+            "cpu_count": 4,
             "bits": "32bit",
-            "processor": "armv6l",
+            "processor": "armv7l",
-            "cpu_desc": "ARMv6-compatible processor rev 7 (v6l)",
+            "cpu_desc": "ARMv7 Processor rev 4 (v7l)",
             "hardware_desc": "BCM2835",
-            "model": "Raspberry Pi Zero W Rev 1.1",
+            "model": "Raspberry Pi 3 Model B Rev 1.2",
-            "total_memory": 439276,
+            "total_memory": 945364,
             "memory_units": "kB"
         },
         "sd_info": {
             "manufacturer_id": "03",
             "manufacturer": "Sandisk",
             "oem_id": "5344",
-            "product_name": "SS08G",
+            "product_name": "SU32G",
             "product_revision": "8.0",
-            "serial_number": "00112233",
+            "serial_number": "46ba46",
-            "manufacturer_date": "9/2017",
+            "manufacturer_date": "4/2018",
-            "capacity": "7.4 GiB",
+            "capacity": "29.7 GiB",
-            "total_bytes": 7948206080
+            "total_bytes": 31914983424
         },
         "distribution": {
             "name": "Raspbian GNU/Linux 10 (buster)",
@@ -866,6 +865,25 @@ Returns: Information about the host system in the following format:
             },
             "like": "debian",
             "codename": "buster"
+        },
+        "available_services": [
+            "klipper",
+            "klipper_mcu",
+            "moonraker"
+        ],
+        "service_state": {
+            "klipper": {
+                "active_state": "active",
+                "sub_state": "running"
+            },
+            "klipper_mcu": {
+                "active_state": "active",
+                "sub_state": "running"
+            },
+            "moonraker": {
+                "active_state": "active",
+                "sub_state": "running"
+            }
         }
     }
 }
@@ -3349,6 +3367,27 @@ sent when an existing user is deleted.
 }
 ```
 
+#### Service State Changed
+Moonraker monitors the state of systemd services it is authorized to track.
+When the state of a service changes the following notification is sent:
+
+```json
+{
+    "jsonrpc": "2.0",
+    "method": "notify_service_state_changed",
+    "params": [
+        {
+            "klipper": {
+                "active_state": "inactive",
+                "sub_state": "dead"
+            }
+        }
+    ]
+}
+```
+
+The example above shows that the `klipper` service has changed to `inactive`.
+
 ### Appendix
 
 #### Websocket setup