fix(docs): enable admonition extension; fix DI steer line breaks (#49)

Two rendering bugs in the DI steer shipped in #48.

1. modern-python.org was serving the literal text '!!! tip "Which one should
   I use?"' with the body as a raw code block. The admonition extension was
   never enabled in mkdocs.yml -- the site had no other admonition, so nothing
   had caught it. mkdocs build --strict passes either way, since a fell-through
   block is valid markdown, just not the markdown you meant.

2. On the org profile, GitHub renders a single newline as <br>, so the
   hard-wrapped paragraph broke mid-sentence in 8 places. The rest of
   profile/README.md avoids this by leaving prose unwrapped.

Both surfaces now carry the steer as two blank-line-separated paragraphs, which
renders identically under GFM and Python-Markdown with no <br> tricks.

Verified: profile renders 4 tables, 0 <br>, 2 <p>; the site renders a real
<div class="admonition tip"> with title + 2 paragraphs and no literal '!!!'.

Author: lesnik512

docs/index.md

@@ -103,6 +103,7 @@ catalog below.
     the resolve path itself stays synchronous, and resources that need to `await` are
     constructed in the framework lifespan
     ([recipe](https://modern-di.modern-python.org/recipes/async-lifespan/)).
+
     [`that-depends`](https://github.com/modern-python/that-depends) is the async-first
     sibling and stays maintained; it ships a migration guide to `modern-di`.
 

mkdocs.yml

@@ -35,6 +35,7 @@ extra_css:
   - stylesheets/extra.css
 
 markdown_extensions:
+  - admonition
   - attr_list
   - md_in_html
   - pymdownx.emoji:

profile/README.md

@@ -21,12 +21,9 @@ Open-source templates and libraries for building production-ready Python applica
 
 ### Dependency injection
 
-**Which one?** Start new projects on [`modern-di`](https://github.com/modern-python/modern-di)
-— a minimal core plus the integrations below. Async apps are first-class: the
-resolve path itself stays synchronous, and resources that need to `await` are built
-in the framework lifespan. [`that-depends`](https://github.com/modern-python/that-depends)
-is the async-first sibling and stays maintained; it ships a migration guide to
-`modern-di`.
+**Which one?** Start new projects on [`modern-di`](https://github.com/modern-python/modern-di) — a minimal core plus the integrations below. Async apps are first-class: the resolve path itself stays synchronous, and resources that need to `await` are built in the framework lifespan.
+
+[`that-depends`](https://github.com/modern-python/that-depends) is the async-first sibling and stays maintained; it ships a migration guide to `modern-di`.
 
 | Project | What it is | Stars | Downloads |
 |---|---|---|---|