Add examples for other IPLD formats

Figuring this out feels like a subtask of https://github.com/ipfs-shipyard/ipld-explorer/issues/55 – cc @jessicaschilling

Right now only three formats are demoed at https://explore.ipld.io (and in ipfs-webui): ipld-dag-pb (unixfvs1), ipld-git and ipld-ethereum:

The app itself imports more codecs, most of them remain unused, which also makes it harder to detect any regressions:

https://github.com/ipfs-shipyard/ipld-explorer/blob/56de6933669fb7e1dd7422616f265c3392ee9a24/src/bundles/index.js#L10-L16

@mikeal @vmx would appreciate your thoughts on:

• Would it be beneficial to IPLD project if https://explore.ipld.io provided more examples?
  • Do you have good/preferred examples of CID for each format?
• What is the canonical term for IPLD formats? (I've seen people mentioning "IPLD format", "codec", "multicodec" and even "block type", clarifying this in IPLD Explorer would make it easier for folks to use a single term)