engine: add chmod a+r for docker.gpg key

Signed-off-by: David Karlsson <[email protected]>

Author: dvdksn

engine/install/debian.md

@@ -97,6 +97,7 @@ Docker from the repository.
     ```console
     $ sudo install -m 0755 -d /etc/apt/keyrings
     $ curl -fsSL {{ download-url-base }}/gpg | sudo gpg --dearmor -o /etc/apt/keyrings/docker.gpg
+    $ sudo chmod a+r /etc/apt/keyrings/docker.gpg
     ```
 
 3.  Use the following command to set up the repository:

engine/install/ubuntu.md

@@ -96,6 +96,7 @@ Docker from the repository.
     ```console
     $ sudo install -m 0755 -d /etc/apt/keyrings
     $ curl -fsSL {{ download-url-base }}/gpg | sudo gpg --dearmor -o /etc/apt/keyrings/docker.gpg
+    $ sudo chmod a+r /etc/apt/keyrings/docker.gpg
     ```
 
 3.  Use the following command to set up the repository: