adds auto-find for secrets files, simplifies docs

verify/test.sh

@@ -90,11 +90,12 @@ if [[ 1 -eq 1 ]]; then
   set +e
   # move 'set -x' within the sub-shell, otherwise all output dumped to tty
   # ... bug: stderr still gets printed, not sure why. E.g. '# RUN: sops updatekeys mock_secrets.yaml'
-  _out="$(set -x; ../bin/update_sops.sh -c "${PWD}" --find_secrets 2>&1 )"
+  _out="$(set -x; ../bin/update_sops.sh -c "${PWD}" --find_secrets "${secrets_file}" 2>&1 )"
   # re-enable strict
   set -e
   set +x
   grep "${_tmp_mock_secrets_filepath}" <<< "${_out}"
+  grep "${secrets_file}" <<< "${_out}"
   set -e
   # TEARDOWN
   rm -rf "${_tmp_mock_secrets_filepath}"