Update multipath / bonding documentation to match reality

[grapexy]

From a week or two of testing ZT multipath, I've learned that following documentation will often lead to many hours of debugging, only to discover that docs were wrong.

Multipath page full of errors. Including outdated enum naming, documenting not currently implemented functionality without a proper disclaimer, documenting sample settings that are outright wrong to name a few. This should be properly updated to fix these issues.

Several issues that I've noticed:

1. Usage of built-in policy names for custom policies:

{
  "settings":
  {
    "defaultBondingPolicy": "balance-aware",
    "policies":
    {
      "balance-aware":
      {
        "basePolicy": "balance-aware",
      }
    }
  }
}

This will result in error: error: custom policy balance-aware will be ignored, cannot use standard policy names for custom policies

2. Docs are using quality key for link quality weights, but ZT expects qualityWeights.
3. balancePolicy for balance-aware does not appear to be used anywhere. I.e. packet-based load-balancing is not currently implemented.
4. I may be wrong on this, but it doesn't look like link speed is taken into account for path selection at all.

In some cases, it's not clear if it's the docs that are wrong, or zt-one, so it would be nice to shine some light on the state of multipath in general. At the very least, I think it's critical to properly label or remove currently unimplemented functionality from the docs.