Add possibility to also update the version in README.md

[epeee]

Goal

Usually, open source projects do have a section in their README.md which shows how to easily add/integrate the project. In shipkit we are currently using

plugins {
    id "org.shipkit.java" version "2.0.0"
}

Let's also update the version in this section in order to always point to the latest version.

Suggested Implementation

TBD