Function leadingZeroBits

leadingZeroBits(hex: string): number
Count NIP-13 leading zero bits of a hex event id.
Parameters
- hex: string
  Lowercase hex string.
Returns number
Number of leading zero bits.
Example
```
leadingZeroBits('000007ab'.padEnd(64, 'f')) === 21;
```
- Defined in packages/mocks/src/domains/pow.ts:190