[Hacktoberfest] Move documentation from Wiki to GitHub

[Dan-Heath]

This PR copies the Label Linked Jobs plugin documentation from the plugins-wiki-docs repo to the label-linked-jobs-plugin repo as part of the Hacktoberfest docs-to-code project. It includes the following changes:

• Copied Readme content from the wiki and merged it with the existing Readme content in the label-linked-jobs-plugin repo
• Copied Change log content from the wiki and created a new CHANGELOG.md file in the label-linked-jobs-plugin repo
• Updated the URL in the pom.xml file for the new location

Please let me know if you have any questions.

• Make sure you are opening from a topic/feature/bugfix branch (right side) and not your main branch!
• Ensure that the pull request title represents the desired changelog entry
• Please describe what you did

[Dan-Heath]

Hello @dominiquebrice and @LinuxSuRen , I created this PR as part of the Hacktoberfest Docs-to-Code project. I think it is ready for review. Please let me know if you have any questions or if you'd like me to make any changes.

[LinuxSuRen]

I will take a look at it later. Thanks for your contribution.