Add links to concepts inhibition and grouping to docs/configuration.md (#3644)

Signed-off-by: Karl-Philipp Richter <[email protected]>

Author: krichter722

docs/configuration.md

@@ -151,6 +151,8 @@ If an alert does not match any children of a node (no matching child nodes, or
 none exist), the alert is handled based on the configuration parameters of the
 current node.
 
+See [Alertmanager concepts](https://prometheus.io/docs/alerting/alertmanager/#grouping) for more information on grouping.
+
 ```yaml
 [ receiver: <string> ]
 # The labels by which incoming alerts are grouped together. For example,
@@ -364,6 +366,8 @@ Inhibition allows muting a set of alerts based on the presence of another set of
 alerts. This allows establishing dependencies between systems or services such that
 only the most relevant of a set of interconnected alerts are sent out during an outage.
 
+See [Alertmanager concepts](https://prometheus.io/docs/alerting/alertmanager/#inhibition) for more information on inhibition.
+
 ### `<inhibit_rule>`
 
 An inhibition rule mutes an alert (target) matching a set of matchers