mixin: move kubernetes to docs, dashboard and rendered rules to contrib

kubernetes/ moves to docs/kubernetes/, dashboard/ to contrib/dashboard/,
and the rendered Prometheus rules and alerts to contrib/monitoring/ with
a README that says how to use and regenerate them.

Signed-off-by: Jan-Otto Kröpke <mail@jkroepke.de>

contrib/mixin/tests/alerts.test.yaml

@@ -1,6 +1,6 @@
 rule_files:
-  - ../windows_rules.yaml
-  - ../windows_alerts.yaml
+  - ../../monitoring/windows_rules.yaml
+  - ../../monitoring/windows_alerts.yaml
 evaluation_interval: 1m
 group_eval_order:
   - windows-exporter-recording

contrib/mixin/tests/resources.test.yaml

@@ -1,6 +1,6 @@
 rule_files:
-  - ../windows_rules.yaml
-  - ../windows_alerts.yaml
+  - ../../monitoring/windows_rules.yaml
+  - ../../monitoring/windows_alerts.yaml
 evaluation_interval: 1m
 group_eval_order:
   - windows-exporter-recording

contrib/mixin/tests/rules.test.yaml

@@ -1,5 +1,5 @@
 rule_files:
-  - ../windows_rules.yaml
+  - ../../monitoring/windows_rules.yaml
 evaluation_interval: 1m
 fuzzy_compare: true