Typo fix in fix-load documentation

[duckling69]

Fix 1471

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#1471

[duckling69]

can you review this? // @aklenik @davidkel

[aklenik]

The issue was only about the fix-load rate controller. Changing the linear-rate (and possibly other) docs is incorrect, since the code indeed uses the startingTps naming.

[davidkel]

You missed changing the description of the options, it still says startingTps

### Options and use
The fixed-load controller can be specified by setting the rate controller `type` to the `fixed-load` string.
Controller options include:
- `startingTps`: the initial rate at which transactions are cumulatively sent to the SUT by all workers
- `transactionLoad`: the number of transactions being processed by the SUT that is to be maintained
The fixed load controller, aiming to maintain a SUT transaction load of 5, with a starting TPS of 100, is specified through the following controller option:
```json
{
  "type": "fixed-load",
  "opts": {
    "transactionLoad": 5,
    "startTps": 100
  }
}

[duckling69]

Thanks for reviewing I think I've done all reviewed changes // @davidkel @aklenik

[davidkel]

LGTM, many thanks for the contribution

I've reviewed the new updates and all looks good