We could use similar comments for imports related to other `@types` packages,
but the need to do it for `@types/embark` (located in
`packages/embark-typings`) seems more pressing since `import ... from "embark"`
statements in the monorepo can be so easily misunderstood.
Note that the comments, and indeed the whole lines, are automatically erased
during babel transpilation of TypeScript since TS types aren't relevant after
the `.js` files are built.
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