object patch rm-link: change arg from 'link' to 'name'

[rcarver]

This improves the docs and semantics of rm-link to be consistent with add-link, clarifying that you should specify the link name as the thing to remove. I found the current docs, <link> ambiguous as to whether it was the name or the hash.

New output for Ipfs object patch --help

USAGE
  ipfs object patch - Create a new merkledag object based on an existing one.

SYNOPSIS
  ipfs object patch

DESCRIPTION

  'ipfs object patch <root> <cmd> <args>' is a plumbing command used to
  build custom DAG objects. It mutates objects, creating new objects as a
  result. This is the Merkle-DAG version of modifying an object.

SUBCOMMANDS
  ipfs object patch add-link <root> <name> <ref> - Add a link to a given object.
  ipfs object patch append-data <root> <data>    - Append data to the data segment of a dag node.
  ipfs object patch rm-link <root> <name>        - Remove a link from a given object.
  ipfs object patch set-data <root> <data>       - Set the data field of an IPFS object.

  Use 'ipfs object patch <subcmd> --help' for more information about each command.

New output for ipfs object patch rm-link --help

USAGE
  ipfs object patch rm-link <root> <name> - Remove a link from a given object.

SYNOPSIS
  ipfs object patch rm-link [--] <root> <name>

ARGUMENTS

  <root> - The hash of the node to modify.
  <name> - Name of the link to remove.

DESCRIPTION

  Remove a Merkle-link from the given object and return the hash of the result.

[Stebalien]

The dock change looks good but the arg change will break a public API. We do sometimes change the API but prefer not to unless there's a strong motivation (i.e., an actual bug).

[Stebalien]

While I prefer this new flat, it breaks the API and I'm not convinced it's really worth the potential issues.

[rcarver]

@Stebalien oh interesting, I assumed the name of positional args wasn't part of a public API. Out of curiosity, where does it cause problems? Is there a test for it?

[Stebalien]

Oh. Sorry, I completely missed the fact that this was positional. This looks fine.