Update ztree repository link

README.org

@@ -531,7 +531,7 @@ Above all, enjoy using Emacs. The community, more than anything, makes Emacs a g
    - [[https://www.emacswiki.org/emacs/SrSpeedbar][Sr Speedbar]] - Same frame speedbar.
      - [[https://github.com/anshulverma/projectile-speedbar][projectile-speedbar]] - Speedbar and Projectile integration.
    - [[https://github.com/emacsorphanage/direx][Direx]] - directory tree explorer.
-   - [[https://github.com/fourier/ztree][ztree]] - Directory tree comparison mode.
+   - [[https://codeberg.org/fourier/ztree][ztree]] - Directory tree comparison mode.
    - [[https://github.com/punassuming/ranger.el][Ranger]] - [[http://ranger.nongnu.org/][ranger]] like file manager based on Dired.
    - [[https://github.com/sunrise-commander/sunrise-commander][Sunrise Commander]] - Twin-pane file manager for Emacs based on Dired and inspired by Midnight Commander.
    - [[https://github.com/Alexander-Miller/treemacs][Treemacs]] - a tree layout file explorer for Emacs.