Improve devex when using @waku/core without @waku/create

[fryorcraken]

This is a change request

Problem

@waku/create was created as a way to provide good easy default for new users of Waku.
A developer wanting to use js-waku can start with @waku/create to get an app running fast.

However, when it comes to bundle size and dependency optimisation, one may not want to rely on the good default of @waku/create and add few lines of code to end up with a smaller package.

This is what the store-js example https://github.com/waku-org/js-waku-examples/blob/master/examples/store-js/index.html attempt to demonstrate, by initializing a Waku with, and only with, the store protocol.

However, it currently rely on @waku/create to initiate libp2p with good defaults:

https://github.com/waku-org/js-waku-examples/blob/671767400a64de886f47d90162ecb937dbe7f21b/examples/store-js/index.html#L17

If you check the network tab of your browser going to https://examples.waku.org/store-js you'll notice the following index.js files being downloaded:

• @waku/create: 2.77 MB
• @waku/core: 1.27MB

Enabling a developer to not use core would be a great gain (do not this include libp2p so the gain may mainly due to not downloading other deps).

Proposed Solutions

Ideally, a user should be able to only depend on @waku/core and libp2p to build the js-store example with a bootstrap peer discovery mechanism.

Not sure if the libp2p setup should be left to the developer (very verbose) or segregated within or outside the @waku/create package.

Out of Scope

Optimising of bundle and size tracked with #579.

[fryorcraken]

Note: Maybe this example is not properly setup for the task as no bundler is used.

The point of this issue/example is to prove that @waku/create is a "good defaults" helpers but is not mandatory to use @waku/core when a developer wants to optimize for size and dependencies.

It may be more appropriate to move the store-js example to a package manager + bundler project form and review the bundle output and size once done.

Then, further decisions can be made to improve the @waku/create API.