dnf-clean: add page (#18174)

* dnf-clean: add page

---------

Co-authored-by: Dylan <145150333+dmmqz@users.noreply.github.com>

pages/linux/dnf-clean.md

@@ -0,0 +1,24 @@
+# dnf clean
+
+> Perform cleanup of temporary files kept for Red Hat-based repositories.
+> More information: <https://dnf.readthedocs.io/en/latest/command_ref.html#clean-command>.
+
+- Remove cache files generated from the repository metadata:
+
+`dnf clean dbcache`
+
+- Mark the repository metadata as expired:
+
+`dnf clean expire-cache`
+
+- Remove repository metadata:
+
+`dnf clean metadata`
+
+- Remove any cached packages from the system:
+
+`dnf clean packages`
+
+- Clean up all DNF repository specific metadata and cached files (all of the above):
+
+`dnf clean all`