docs release v1.9.2

• Add Azure Lighthouse delegation (https://github.com/giantswarm/docs/pull/532)
• Adjust list line-height and overall appearance (https://github.com/giantswarm/docs/pull/534)
• Document the gsctl GSCTL_AUTH_TOKEN environmental variable (https://github.com/giantswarm/docs/pull/537)
• Document the gsctl list clusters --sort flag (https://github.com/giantswarm/docs/pull/538)