public/protected/private colouring

[larshp]

https://marketplace.visualstudio.com/items?itemName=oderwat.indent-rainbow
https://marketplace.visualstudio.com/items?itemName=GauravSharma.colorized-access-modifier

colours

https://github.com/scalameta/lsp-example/blob/master/lsp-example-vscode/src/decoration-protocol.ts
https://vscode.rocks/decorations/
https://github.com/microsoft/vscode-extension-samples/tree/main/decorator-sample