ensure the existence of @fireproof/encrypted-blockstore

[mabels]

From the 0.19 version we abandon the https://www.npmjs.com/package/@fireproof/encrypted-blockstore @jchris wants the SEO of this "sub" aspect of the core to be visible. So we have to ensure that with every /core release we also have a encrypted-blockstore is released. We should use the same approach as use-fireproof package which proxied the core. And to ensure that this sub-functionality is working we need to build a test from the docs/readme, and update the readme accordingly.