[WIP] Platform initial setup

[kimjoar]

Very initial setup stuff for #9675, this is just to demo some ideas. (Still missing tons of tests.)

This contains basic setup for Flow, rxjs, the cli and config files.

Copying what I put in platform/README.md for now:

Flow

First install flow-typed:

npm install -g flow-typed

Then run:

flow-typed install

This pulls (or generates empty) Flow libdefs for dependencies into the ./flow-typed folder.

(If we keep Flow we'll follow the recommended setup and commit flow-typed/ to our repo.)

Types in VSCode

To get Flow running in VSCode:

$ cat .vscode/settings.json
{
  "flow.enabled": true,
  "flow.useNPMPackagedFlow": true,
  "flow.stopFlowOnExit": true,
  "javascript.validate.enable": false
}

For other editors check out https://flow.org/en/docs/editors/

Running code

Just shows the parsed config:

node scripts/platform.js -c ./config/kibana.dev.yml

With failure (for now, as logging is missing in the schema):

node scripts/platform.js -c ./config/kibana.dev.yml -q

[epixa]

Can we do this with a devDependency instead? People shouldn't need to self-manage npm dependencies or use global installs.

[kimjoar]

Closing in favour of new upcoming PR.