v0.40

Update grafana dashboard docs

Instructions to add Grafana dashboard do not work. The proposed
functions are wrong, according to
[grafana.libsonnet](https://github.com/brancz/kubernetes-grafana/blob/master/grafana/grafana.libsonnet)
`dashboards` and `rawDashboards` should be used in `grafana+::`
field.

This PR updates the existing documentation and fixes minor typos.

Update release-0.5 compatibility

kubernetes-mixin release-0.4 is only supported by 1.18+

Signed-off-by: Damien Grisonnet <dgrisonn@redhat.com>

Update kubelet config section and compatibility

This readme update includes two changes:
 1) Update the kubelet config requirements to mention the modern (non-deprecated) kubelet configuration values that can be used in place of the flags
 2) Update the compatibility matrix to mention the issue running release-0.4 on kubernetes versions 1.16.2 through 1.16.4, including a workaround.

update compatibility matrix with note for release-0.4

Node exporter ignore pod mounts

update generated files for prometheus operator v0.39.0

The ignored filesystem types now matches the default, so the
comment and arg can be removed.

Ignore kubelet pod filesystem mounts of the form:
/var/lib/kubelet/pods/1b260ce7-e75d-44d4-8409-922d2bd0851f/volumes...
Metrics for these volumes are available via the kubelet_volume_stats*
metrics.

Revert "Remove field preserveUnknownFields from CRDs"

custom metrics v1beta2 api with k8s-prometheus-adapter v0.7.0

This reverts commit cdaaf3d5.

Update prometheus version to v2.17.2

Signed-off-by: Benjamin <benjamin@yunify.com>

Fix json files cleanup when generating manifests

Signed-off-by: Damien Grisonnet <dgrisonn@redhat.com>

Remove version label from node-exporter selectors

fix readme typos

Transform custom-metrics into an addon

Test against kubernetes 1.18 release

Bump dependencies