:book: Add instructions on common tasks: Linting and Conversions

/kind feature

Describe the solution you'd like [A clear and concise description of what you want to happen.]

Add to the developer guide how to:

• Handle linting (e.g. using GCI as your formatter, including configs for Goland and VS Code)
• Do conversions using CAPI's utilconversion

Anything else you would like to add: [Miscellaneous information that will assist in solving the issue.]

Environment:

• Cluster-api-provider-vsphere version:
• Kubernetes version: (use kubectl version):
• OS (e.g. from /etc/os-release):

/kind documentation