Enable all main body Markdown options for summaries

This fixes odd renderings when these features are used in the first
paragraph of documentation for an item. This is an extension of #87270.

src/librustdoc/html/markdown.rs

@@ -56,9 +56,13 @@ pub(crate) fn main_body_opts() -> Options {
         | Options::ENABLE_SMART_PUNCTUATION
 }
 
-/// A subset of [`main_body_opts()`] used for rendering summaries.
+/// Options for rendering Markdown in summaries (e.g., in search results).
 pub(crate) fn summary_opts() -> Options {
-    Options::ENABLE_STRIKETHROUGH | Options::ENABLE_SMART_PUNCTUATION | Options::ENABLE_TABLES
+    Options::ENABLE_TABLES
+        | Options::ENABLE_FOOTNOTES
+        | Options::ENABLE_STRIKETHROUGH
+        | Options::ENABLE_TASKLISTS
+        | Options::ENABLE_SMART_PUNCTUATION
 }
 
 /// When `to_string` is called, this struct will emit the HTML corresponding to