Add CID Column

[lidel]

fiatjaf: why doesn't the gateway http output for unixfs dirs show the hashes of linked files?

Good question!

• I suspect CIDs could be easily added to listing, next to the Size column
• CIDs could be clickable links that open item as a new "root path"
  • this also enables users to copy direct link to image or a subdirectory
• It probably requires changes to https://github.com/ipfs/dir-index-html and then switching go-ipfs to new version

cc @olizilla @fiatjaf

[jessicaschilling]

Closing this one in favor of the combined dir-index-html UI bounty issue here: #37