Merge pull request ipfs/boxoipfs/interface-go-ipfs-core#26 from hinshun/pin-rm-docs

Update Pin.RmRecursive docs to clarify shared indirect pins are not removed This commit was moved from ipfs/interface-go-ipfs-core@c140b0fa383113acd3f80ec333e7a82d20aaee8f This commit was moved from ipfs/boxo@25b99950743567c71767e8b1f960fea1f3f24f0d