feat: document deprecated RPC API commands

[lidel]

Leverages Status field from ipfs/go-ipfs-cmds#225 + ipfs/kubo#8802 and uses that information while generating HTTP RPC API reference docs.

• "Experimental" and "Deprecated" commands are listed in separate sections after regular ones
• Each command has additional warning box informing about deprecated/experimental state, in case someone opens its docs via direct link

Demo

These additional annotations are not present in go-ipfs 0.12, but will be present when 0.13 ships.

For now, I generated docs/reference/http/api.md using this PR for easier preview:

• https://bafybeietbmpk2lj2vs23optcn4ar6ru4qj5wnr65dygzm5zukwspeay7c4.ipfs.cf-ipfs.com/reference/http/api/#deprecated-rpc-commands
• https://bafybeietbmpk2lj2vs23optcn4ar6ru4qj5wnr65dygzm5zukwspeay7c4.ipfs.cf-ipfs.com/reference/http/api/#experimental-rpc-commands

[lidel]

• Switched to go-ipfs-cmds v0.7.0 which includes Deprecated flags/options go-ipfs-cmds#93
• Merged feat(cmds): document deprecated RPC API commands kubo#8802 – we are now waiting for go-ipfs 0.13 to ship, then we can switch this PR to 0.13.0 and re-generate docs/reference/http/api.md before merging.

[filecorgi]

• Image optimization came back clean!
• Vuepress build was successful!

[lidel]

I rebased this to build docs for already released go-ipfs 0.12.2, this way we can merge it without waiting for 0.13.