This is a preparation for `monaco-editor@^0.22.0`. In this version the global
`monaco` object was removed for ESM users.
A choice was made to use `monaco-editor` imports, because this probably has
best compatibility for most users. If users want to use `monaco-editor-core`,
they will have to create an alias in their own build process.
Since both yaml-language-server and prettier are included in the bundle, their
versions should match for best compatibility. Also code has been formatted using
the updated prettier.
Jest, eslint, and typescript-tslint-plugin were installed, but never used. Node
types were used for timers, but this is incorrect, as this code is supposed to
run in the browser.
