Restore the docstring the guard suite's docstring gate requires

Earlier editing of the guard suite dropped the docstring on stepIndex, and the
constant holding the workflow source was never documented. Packages that gate on
100% docstring coverage fail on both. Caught by pm-presets, whose gate runs over
its test tree, and fixed everywhere for consistency.

Tracked as pm-github-yq1d.

Author: unbraind

test/release-workflow.test.ts

@@ -3,11 +3,22 @@ import { readFileSync } from "node:fs";
 import { resolve } from "node:path";
 import test from "node:test";
 
+/** The release workflow source, read once and asserted against as text. */
 const workflow = readFileSync(
   resolve(import.meta.dirname, "../.github/workflows/release.yml"),
   "utf-8"
 );
 
+/**
+ * Locate a named workflow step so tests can assert on ordering between steps.
+ *
+ * Offsets are taken against the raw source rather than a comment-stripped copy:
+ * removing text shifts every index after it, which would silently corrupt the
+ * ordering comparisons these offsets exist to support.
+ *
+ * @param name - The exact `- name:` value of the step.
+ * @returns The character offset of that step within the workflow source.
+ */
 function stepIndex(name: string): number {
   const escapedName = name.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
   const match = new RegExp(