added proper docker install as dnf5 have no config-manager

in the fedora 40 and above dnf5 is implemented and hence the dnf command listed in the docker will not work. I have updated the dnf command to dnf-3 as then you will be able to use the same.

Author: Gaurav Sablok

content/manuals/engine/install/fedora.md

@@ -83,7 +83,7 @@ your DNF repositories) and set up the repository.
 
 ```console
 $ sudo dnf -y install dnf-plugins-core
-$ sudo dnf config-manager --add-repo {{% param "download-url-base" %}}/docker-ce.repo
+$ sudo dnf-3 config-manager --add-repo {{% param "download-url-base" %}}/docker-ce.repo
 ```
 
 #### Install Docker Engine