VSCode syntax extension

# Intellisense for envoy configuration files (yaml)

Having to lookup keywords in documentation causes a slower developer feedback loop. yaml indentation can also be be a challenge to get right at first attempt with deeply nested structures.

Intellisense can help you quickly get feedback on which keywords are available, which also tells you which "depth" you are at within the yaml tree structure.

An example of an extension like this is the Kubernetes extension for VSCode - providing intellisense for Kubernetes resource definition files (which also uses yaml files)

## Relevant links
- https://github.com/redhat-developer/yaml-language-server
- https://github.com/Azure/vscode-kubernetes-tools