Spark On K8S 0.7.0

What's Changed

• dev: Create the doc with mkdocs and deploy to gh page by @hussein-awala in #52
• feat(airflow): Implement an operator link for Spark app and history UIs by @hussein-awala in #49
• test(airflow): add tests for SparkOnK8SOperatorLink by @hussein-awala in #54
• doc: improve examples doc by @hussein-awala in #56
• security: Stop returning the exception details to the API users by @hussein-awala in #57
• chore(helm): Improve the chart doc and migrate to SemVer versioning by @hussein-awala in #58
• docs(helm): add helm chart doc to the gh page by @hussein-awala in #59

Full Changelog: 0.6.0...0.7.0