Example sketch TickerParameter.ino implementation doesn't match its comments

### Basic Infos

- [x] This issue complies with the [issue POLICY doc](https://github.com/esp8266/Arduino/blob/master/POLICY.md).
- [x] I have read the documentation at [readthedocs](https://arduino-esp8266.readthedocs.io/en/latest) and the issue is not addressed there.
- [x] I have tested that the issue is present in current master branch (aka latest git).
- [ ] I have searched the issue tracker for a similar issue.
- [ ] If there is a stack dump, I have decoded it.
- [x] I have filled out all fields below.

#### Platform

n/a

### Settings in IDE

n/a

### Problem Description

The example sketch [TickerParameter.ino](https://github.com/esp8266/Arduino/blob/19b7a29720a6f2c95d06e2ea4baa335dcf32e68f/libraries/Ticker/examples/TickerParameter/TickerParameter.ino)

says in comment:

> This sample runs two tickers that both call one callback function, but with different arguments.

However, implementations used three `Ticker` instances. A callback function with a parameter is used on one of them but always with same parameter. I suspect this example may have been left in a work-in-progress state and never completed.