Adding WordPress Package Link Generator

[srtfisher]

Adds WordPress plugin/theme link generation to the package name via WordPress Packagist.

Example:

| Prod Packages                                                      | Operation | Base | Target | Link |
|--------------------------------------------------------------------|-----------|------|--------|------|
| [wpackagist-plugin/jetpack](https://wordpress.org/plugins/jetpack) | Upgraded  | 13.1 | 13.9   |      |

[codecov]

Codecov Report

Attention: Patch coverage is 92.30769% with 1 line in your changes missing coverage. Please review.

Project coverage is 99.84%. Comparing base (4f10027) to head (844bd11).

Files with missing lines	Patch %	Lines
src/Url/WordPressGenerator.php	91.66%	1 Missing ⚠️

Additional details and impacted files

@@              Coverage Diff              @@
##                main      #36      +/-   ##
=============================================
- Coverage     100.00%   99.84%   -0.16%     
- Complexity       216      221       +5     
=============================================
  Files             21       22       +1     
  Lines            579      650      +71     
=============================================
+ Hits             579      649      +70     
- Misses             0        1       +1     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[IonBazan]

Hi @srtfisher, thanks for your contribution! I refactored it a bit to keep the compatibility with PHP 5.3 but I noticed there is a simpler way to achieve similar goals. I'm also afraid that packages hosted elsewhere but for some reason starting with the wpackagist-plugin marker will be forced to use the same URL generator, even if hosted on github or somewhere else.
Since your solution only provides the release URL, we might as well default to the package's homepage field instead as demonstrated in #37 - feel free to check it out and let me know if that works for you.