fix(release-pill): docstring no longer terminates outer HTML comment early

The note at lines 36-42 explained why you should not write literal `<!-- ... -->` inside the docstring, and in doing so, wrote literal `<!-- ... -->` inside the docstring. HTML disallows nested comments, so the inner `-->` token in the warning text closed the outer comment on line 1, leaking the example markup (span and script tags) into the rendered page on every Quarto site that included this snippet via include-after-body. The leaked script tag carries a literal U+2026 ellipsis as part of its src attribute (the docstring abbreviated the path), so every page fetched a 404 for `<subsite>/…release-pill.js`.

Rewrites the note to describe the rule without using the literal characters it warns against. The outer comment now opens on line 1 and closes on line 61 with no intermediate delimiters.

After this lands, the release-pill 404 disappears across vol1, vol2, tinytorch, kits, mlsysim, and instructors. The actual release-pill JS (inline script at the bottom of this file) was always intact — only the leak from the bad docstring was failing.

Author: profvjreddi

shared/release/release-pill.html

@@ -33,13 +33,14 @@
 
   (See shared/release/release-pill.js for the standalone JS form.)
 
-  NOTE: Do NOT use a nested `<!-- ... -->` HTML comment in this docstring
-  block. HTML disallows nested comments, so the inner `-->` would
-  terminate the outer comment early and cause the example markup below
-  it (the `<span data-release-pill>` and `<script src=…release-pill.js>`)
-  to leak into the rendered page — producing a 404 on every Quarto site
-  that includes this snippet via `include-after-body`. Use `//`-style
-  pseudo-comments inside the documentation block instead.
+  NOTE: This docstring must not contain literal HTML-comment delimiters
+  (open or close). HTML disallows nested comments, so an inner close
+  delimiter would terminate this outer comment early and leak the
+  example markup below it (the span and script tags) into the rendered
+  page — producing a 404 on every Quarto site that includes the snippet
+  via include-after-body. The earlier version of this note tripped that
+  exact bug; if you need to describe HTML-comment syntax, do it without
+  using the literal characters.
 
   ── Manifest contract ──