Markdownize docstring a little bit

include/testing.sh

@@ -27,10 +27,10 @@ collect_artifacts() {
     #
     # Usage: collect_artifacts [[+]target]
     #
-    # If target starts with plus sign, the value is first passed
-    # to `date` utility and output is replaced. If target is not
-    # given, `$FFOO_TESTING_ARTIFACTS`, or a hard-coded value
-    # "+artifacts--%Y%m%d-%H%M%S" is used.
+    # If *target* starts with plus sign, the value is first
+    # passed to `date` utility and output is replaced. If
+    # *target* is not given, `$FFOO_TESTING_ARTIFACTS`, or
+    # a hard-coded value `+artifacts--%Y%m%d-%H%M%S` is used.
     #
     local aroot="$1"
     aroot=${aroot:-$FFOO_TESTING_ARTIFACTS}