Docs: Add support for Monorepo project docs generation

Following up on the conversation [here](https://github.com/ipfs/aegir/pull/1107#issuecomment-1328126285) we should work out a way to handle generating docs for monorepos.

TypeDoc's `entryPointStrategy: packages` is dedicated support for monorepo projects, it will attempt to determine entry points based on `package.json`'s main property (with default value `index.js`) and if it wasn't found, based on `types` property.

For most for aegir-managed projects monorepos seem to have the projects listed under the `packages` directory, we could default to this and use the [packages entryPointStrategy](https://typedoc.org/guides/options/#entrypointstrategy) and pass the paths.

Otherwise we could have an optional `monoRepoEntryPoints` flag that a user could pass as an argument and then we pass that to the `entryPointStrategy` argument.