fix: Pino options have a generic type

[UndefinedBehaviour]

Issue

import { pinoHttp } from 'pino-http';

const httpLogger = pinoHttp({
    customLevels: {
        log: 20,
    },
});

const logger = httpLogger.logger;

function f(level: 'warn' | 'info' | 'log', message: string): void {
  logger[level](message);
}

This code is correct but currently throws a ts(7053) : Element implicitly has an 'any' type because TS can't see the custom level added in the configuration.

[kibertoad]

Please add tsd test for it!

[UndefinedBehaviour]

Test added!

[mcollina]

lgtm

test added