docs: remove the source link from every skills page

Every docs page opened with a [Source](github.com/...) link, and
.agents/writing-docs.md told agents to add one to each new page.
Remove the line from all 25 pages, rewrite the one inline use in
ask-matt.md, and drop the rule from the page template, the fixed
frame list, and the "Done when" list so the links do not come back.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

docs/productivity/grill-me.md

@@ -1,5 +1,3 @@
-[Source](https://github.com/mattpocock/skills/tree/main/skills/productivity/grill-me)
-
 ## What it does
 
 `grill-me` takes a **loose idea** and interviews you until it has real decisions in it. You do not need a worked-out plan to start — producing one is what the session is for. It asks in **rounds**: each round is the whole **frontier** — every question whose prerequisites you have already settled — so you are never asked something that hinges on an answer it hasn't heard yet.

docs/productivity/grilling.md

@@ -1,5 +1,3 @@
-[Source](https://github.com/mattpocock/skills/tree/main/skills/productivity/grilling)
-
 ## What it does
 
 `grilling` is the relentless interview that stress-tests a plan or design before you build it. It maps the plan as a **design tree** — every decision branches into the decisions that hang off it — and works that tree in **rounds** until you and the agent share the same understanding.

docs/productivity/handoff.md

@@ -1,5 +1,3 @@
-[Source](https://github.com/mattpocock/skills/tree/main/skills/productivity/handoff)
-
 ## What it does
 
 `handoff` compacts the current conversation into a **handoff document** — a single write-up a fresh agent can read to pick up the work where you left off.

docs/productivity/teach.md

@@ -1,5 +1,3 @@
-[Source](https://github.com/mattpocock/skills/tree/main/skills/productivity/teach)
-
 ## What it does
 
 `teach` turns the current directory into a standing teaching workspace and teaches you one topic across many sessions — devising short, beautiful, interactive lessons tied to *why* you want to learn.

docs/productivity/to-questionnaire.md

@@ -1,5 +1,3 @@
-[Source](https://github.com/mattpocock/skills/tree/main/skills/productivity/to-questionnaire)
-
 ## What it does
 
 `to-questionnaire` turns a decision you can't settle on your own into a **questionnaire** — a Markdown document you hand to the one person who holds what you're missing, to fill in async or work through together in a meeting.

docs/productivity/wait-what.md

@@ -1,5 +1,3 @@
-[Source](https://github.com/mattpocock/skills/tree/main/skills/productivity/wait-what)
-
 ## What it does
 
 `wait-what` is the fire extinguisher for a message that didn't land. You fire it the moment you lose the thread, and the agent re-pitches what it just said: a little of the context you were missing, plain English, and the vocabulary from your project's `CONTEXT.md`.

docs/productivity/writing-for-agents.md

@@ -1,5 +1,3 @@
-[Source](https://github.com/mattpocock/skills/tree/main/skills/productivity/writing-for-agents)
-
 ## What it does
 
 `writing-for-agents` is the reference you write agent-facing documents against — skills, `AGENTS.md` / `CLAUDE.md`, and any doc an agent reaches by a pointer. The packaging differs; the writing does not: the same levers make each one predictable, so the agent takes the same *process* every run rather than producing the same output.