Add support to set a year or year range dynamically from the year range extracts from the previous header

[jeradrutnam]

This will add a feature to the plugin that can control the year in the template option using a placeholder in the template.

Usage :

// eslintrc.js

"rules": {
    "header/header": [
        2, 
        "block", 
        [{ "pattern": " Copyright \\d{4}", "template": " Copyright {{year}}" }, "My Company"],
        {
            "templateOptions": {
                "forceEndYear": false,
                "endYear": 2022,
                "endYearPersist": true,
                "startYear": new Date().getFullYear(),
                "startYearPersist": true,
                "yearRange": true,
                "yearRangeValidations": true
            }
        }
    ]
}

Will allow to extract year from the preious header and manipulate it to a required format: "YYYY" or "YYYY-YYYY".

Addressed issues: #33 #27 #38

@Stuk, first of all thanks for the plugin.

And I'm not sure if this PR covers all the scenarios. Please do let me know if need to do any improvements to it. As I only focused on the block license header comments. Which was my requirement.

[eduardo-vargas]

Any updates on this PR ?

[jeradrutnam]

Any updates on this PR ?

Looks like the project is no longer active. So, we are also using the one that I forked and improved. You are also free to use it.

[tonyganchev]

I forked https://github.com/tonyganchev/eslint-plugin-header/ and publish new versions and would love to review the change.