Crystal: Update known failures.

examples/prism-crystal.html

@@ -13,18 +13,4 @@ end</code></pre>
 	def {{ key.id }}
 		{{ value }}
 	end
-{% end %}</code></pre>
-
-<h2>Known failures</h2>
-<p>There are certain edge cases where Prism will fail.
-	There are always such cases in every regex-based syntax highlighter.
-	However, Prism dares to be open and honest about them.
-	If a failure is listed here, it doesn’t mean it will never be fixed. This is more of a “known bugs” list, just with a certain type of bug.
-</p>
-
-<h3>Attriubte-like substrings</h3>
-<pre><code>" @[AlwaysInline] "</code></pre>
-
-<h3>Macro expansions in strings</h3>
-<pre><code>" {{ foo }} "
-" {% bar %} "</code></pre>
+{% end %}</code></pre>