docs: add docs for the autoscaler on_error and on_check_error con…

…figuration

website/content/tools/autoscaling/policy.mdx

@@ -40,6 +40,14 @@ horizontal application scaling or horizontal cluster scaling.
   omitted the configuration value [default_evaluation_interval][eval_interval_agent]
   from the agent will be used.
 
+- `on_check_error` - Defines how to handle errors during check evaluation.
+  Possible values are `"fail"` or `"ignore"`. If set to `"fail"` the policy
+  evaluation will stop if any [`check`](#check) returns an error and no
+  scaling action will take place. If set to `"ignore"` any errors returned by a
+  `check` will be ignored when computing the scaling action. This value may be
+  overridden individually by setting [`on_error`](#on_error). Defaults to
+  `"ignore"`.
+
 - `target` - Defines where the autoscaling target is running. Detailed information
   on the configuration options can be found on the [Target Plugins][target_plugin_docs]
   page.
@@ -59,6 +67,13 @@ horizontal application scaling or horizontal cluster scaling.
 - `query_window` - Defines how far back to query the APM for metrics. It should
   be provided as a duration (e.g.: `"5s"`, `"1m"`). Defaults to `1m`.
 
+- `on_error` - Defines how to handle errors during the `check` evaluation.
+  Possible values are `"fail"` or `"ignore"`. If set to `"fail"` the policy
+  evaluation will stop in case an error occurs and not scaling action will take
+  place. If set to `"ignore"` the result of this `check` will not be taken into
+  considation when computing the scaling action. If not set the value of
+  [`on_check_error`](#on_check_error) will be used.
+
 - `strategy` - The strategy to use, and it's configuration when calculating the
   desired state based on the current count and the metric returned by the APM.
   Detailed information on the configuration options can be found on the