update mirror fork card

external/contribute/mirror-fork/mirror-fork.md

@@ -17,7 +17,7 @@ you should follow the follow simple steps.
 2. Expand the section on `Mirroring repositories`
 3. In the field `Git repository URL`, enter the SSH clone address from the main repository. 
 
- <img src="img/img1.png">
+    <img src="img/img1.png">
 
 4. Select `Mirror Direction` as `Pull`
 5. Click on `Detect Host Keys`
@@ -30,9 +30,10 @@ You will see an entry in the table below the blue button. Often, there is an err
 
     <img src="img/copy-ssh-key.png" height="80">
 
-2. Then, browse to your profile picture (top right) and click on `Preferences`
-3. On the left of the page, click on `SSH keys`
-4. Paste the key (using CTRL+V or CMD+V) into the SSH field
-5. Click on `Add key`
+2. Then, browse to your profile picture (top left corner) and click on `Preferences`
+3. On the left of the page, click on `SSH Keys`
+4. Click on the 'Add new key' button on the SSH keys table
+5. Paste the key (using CTRL+V on Windows or CMD+V on macOS) into the SSH key field
+6. Click on `Add key`
 
 Now, the synchronization of the fork should perform successfully. You can click on the sync button or wait a few minutes. :white_check_mark: