Add auto-update support and update documentation links

Introduced Wupz_Updater class to enable plugin auto-updates via GitHub releases and integrated it into the main plugin. Updated all documentation and support links to point to the new official documentation site (https://docs.wups.org) in README.md, settings, and readme.txt.

Merge pull request #6 from danielgtmn/wordpress-fixxes

Refactor backup directory checks and enhance security measures

Merge pull request #4 from danielgtmn/deployment

Update build-plugin.yml