doc: fix typo on Fedora documentation

Signed-off-by: Patrizio Bekerle <[email protected]>

Author: pbek

webpage/src/installation/fedora.md

@@ -37,7 +37,7 @@ Please note that the portion "Fedora_40" in the above code should reflect the ve
 
 Use this method if your Fedora version doesn't support the `config-manager` dnf plugin, run these commands as root.
 
-Run the following shell commands as root to trust the repository.
+Run the following shell command as root to trust the repository.
 
 ```bash
 rpm --import http://download.opensuse.org/repositories/home:/pbek:/QOwnNotes/Fedora_40/repodata/repomd.xml.key