[release-2.5] Update dashboard screenshots in docs (#3577)

* update screenshots (#3553)

(cherry picked from commit e2fa561)

* empty space

Signed-off-by: Mauro Stettler <mauro.stettler@gmail.com>

* Revert "empty space"

This reverts commit c8616a8.

Signed-off-by: Mauro Stettler <mauro.stettler@gmail.com>
Co-authored-by: Mauro Stettler <mauro.stettler@gmail.com>

operations/mimir-mixin-tools/screenshots/run.sh

@@ -13,7 +13,7 @@ GRAFANA_PID=""
 if [ ! -e "${SCRIPT_DIR}/.config" ]; then
   echo "This tool expects a local config file stored at ${SCRIPT_DIR}/.config and containing the following content:"
   echo ""
-  echo "CLUSTER=\"<cluster-to-query\""
+  echo "CLUSTER=\"<cluster-to-query>\""
   echo "MIMIR_NAMESPACE=\"<namespace-where-mimir-is-running>\""
   echo "ALERTMANAGER_NAMESPACE=\"<namespace-where-alertmanager-is-running>\""
   echo ""