Add a YAML lint make target

[DhritiShikhar]

In addition to go lint, a YAML lint could also be added for all the YAML files:

YAML_FILES := $(shell find . -path ./vendor -prune -o -path ./config -prune -o -type f -regex ".*\.y[a]ml" -print)
.PHONY: lint-yaml
## Runs yamllint on all yaml files
lint-yaml: ${YAML_FILES}
    $(Q)$(PYTHON_VENV_DIR)/bin/pip install yamllint==1.23.0
    $(Q)$(PYTHON_VENV_DIR)/bin/yamllint -c .yamllint $(YAML_FILES)

[openshift-bot]

Issues go stale after 90d of inactivity.

Mark the issue as fresh by commenting /remove-lifecycle stale. Stale issues rot after an additional 30d of inactivity and eventually close. Exclude this issue from closing by commenting /lifecycle frozen.

If this issue is safe to close now please do so with /close.

/lifecycle stale

[openshift-bot]

Stale issues rot after 30d of inactivity.

Mark the issue as fresh by commenting /remove-lifecycle rotten. Rotten issues close after an additional 30d of inactivity. Exclude this issue from closing by commenting /lifecycle frozen.

If this issue is safe to close now please do so with /close.

/lifecycle rotten /remove-lifecycle stale

[openshift-bot]

Rotten issues close after 30d of inactivity.

Reopen the issue by commenting /reopen. Mark the issue as fresh by commenting /remove-lifecycle rotten. Exclude this issue from closing again by commenting /lifecycle frozen.

/close

[openshift-ci[bot]]

@openshift-bot: Closing this issue.

In response to [this](https://github.com/openshift/external-dns-operator/issues/145#issuecomment-1259131735): >Rotten issues close after 30d of inactivity. > >Reopen the issue by commenting `/reopen`. >Mark the issue as fresh by commenting `/remove-lifecycle rotten`. >Exclude this issue from closing again by commenting `/lifecycle frozen`. > >/close Instructions for interacting with me using PR comments are available [here](https://git.k8s.io/community/contributors/guide/pull-requests.md). If you have questions or suggestions related to my behavior, please file an issue against the [kubernetes/test-infra](https://github.com/kubernetes/test-infra/issues/new?title=Prow%20issue:) repository.