fix: silence the spell checker on a generated anchor that strips an apostrophe

CI's hygiene job went red on typos, and the finding is real rather than a
false positive worth arguing with: the table-of-contents row this branch
generated for design-level.md carries the anchor
#domain-events-in-depth-why-theyre-special, and "theyre" is a word the checker
corrects to "their" or "there".

The anchor cannot be spelled any other way. GitHub's slugger strips apostrophes,
so a heading containing a contraction produces exactly that token, and changing
it breaks the link. The heading itself, "Domain Events in Depth (Why They're
Special)", is pre-existing and out of this branch's scope to reword.

So the generated block carries the repo's markdown spellchecker directive, and
the suppression costs no coverage: every row in a table of contents echoes a
heading that is still spell-checked where it is actually written, further down
the file. A genuine typo in that heading would still be caught there.

Scoped to the one block rather than added to _typos.toml, which is the
constellation-wide synced policy and says plainly that a repo-specific exception
does not belong in it.

Verified: typos exits 0 over the tree, markdownlint clean on the file, and all
124 tables of contents still resolve with zero dangling anchors.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FTVH5ZRVph75kvxzUAnb6q

Author: claude

plugins/event-storming/skills/methodology/reference/design-level.md

@@ -2,6 +2,13 @@
 
 ## Contents
 
+<!-- spellchecker:off -->
+<!-- Anchor targets are GitHub's slugs, which strip apostrophes, so a heading
+     with a contraction yields a token the spell checker reads as a misspelling
+     ("They're" becomes "theyre"). The slug has to keep that form for the link
+     to resolve. Suppression is scoped to this generated block and costs no
+     coverage: each row echoes a heading that is still checked where it is
+     written, below. -->
 - [How Design-Level Differs from Big Picture and Process Modeling](#how-design-level-differs-from-big-picture-and-process-modeling)
 - [Working with the Big Picture Artifact](#working-with-the-big-picture-artifact)
 - [Design-Level Workshop Phases `\[SUPPLEMENTED\]`](#design-level-workshop-phases-supplemented)
@@ -11,6 +18,7 @@
 - [From EventStorming to User Stories](#from-eventstorming-to-user-stories)
 - [Domain Events in Depth (Why They're Special)](#domain-events-in-depth-why-theyre-special)
 - [Relationship to Your Architecture](#relationship-to-your-architecture)
+<!-- spellchecker:on -->
 
 Design-Level EventStorming bridges the gap between process understanding and software implementation. It focuses on implementing software features that solve a specific problem, working within a single bounded context.