Add initial TS configuration

This issue is the first step towards implementation of Standardise TypeScript config (tsc, eslint) acr... (gitlab-org/editor-extensions/meta#85) and closes Add typescript config to gitlab eslint-plugin (gitlab-org/editor-extensions/meta#121).

The goal of this change is to add a typescript related configuration that we can use for our TypeScript code bases. The typescript config would inherit base js rules that are not vue.js specific, plus adds a few TS specific rules and overrides. Overall it should lead to more uniform styles accross our javascript and typescript projects.