docs(grilling): pin the question format and document it

Add the fixed per-question shape (numbered title, body, recommendation
line) to grilling's SKILL.md, sync the docs page, and add a changeset.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

skills/productivity/grilling/SKILL.md

@@ -7,6 +7,14 @@ Interview the user relentlessly until you reach a shared understanding. Map this
 
 Work the tree in **rounds**. The **frontier** is every decision whose prerequisites are already settled — the questions you can ask _now_ without guessing at answers you haven't heard yet. Ask the whole frontier in one round: number each question and give your recommended answer. Then wait for the user's answers before the next round.
 
+Each question should be formatted like so:
+
+```
+**Q1** - <question title>: <question body, might be multiple paragraphs, including multiple choices>
+
+➡️ **Recommendation:** <your recommended answer>
+```
+
 Each round the user answers reshapes the tree — settled decisions push the frontier outward and unblock questions that depended on them. Recompute the frontier and ask the next round. A question whose answer depends on another question still open in this round belongs to a _later_ round, not this one.
 
 Finding _facts_ is your job, never the user's. When a frontier question needs a fact from the environment (filesystem, tools, etc.), dispatch a sub-agent to find it — don't ask the user for anything you could look up yourself. Don't block on it: a running exploration is an unsettled prerequisite, so only the questions downstream of it wait for the sub-agent to report — ask the rest of the frontier now. The _decisions_ are the user's — put each to them and wait.