Function towardZero

towardZero(bipolarValue: number, amount: number): number
Pushes a bipolar value toward zero by amount. Return value is clamped on bipolar range of -1..1
```
import { Bipolar } from 'https://unpkg.com/ixfx/dist/data.js';
Bipolar.towardZero(-1, 0.1); // -0.9
Bipolar.towardZero( 1, 0.1); //  0.9
Bipolar.towardZero( 0, 0.1); //  0.0
Bipolar.towardZero( 1, 1.1); //  0.0
```
If amount is greater than 1, 0 is returned. Throws an error if bipolarValue or amount are not numbers. Throws an error if amount is below zero.
Parameters
- bipolarValue: number
  Bipolar value to nudge toward zero
- amount: number
  Amount to nudge by
Returns number
Bipolar value -1...1