Rollup merge of #55161 - akxcv:rustdoc/disable-spellcheck, r=QuietMisdreavus,GuillaumeGomez

[librustdoc] Disable spellcheck for search field

This disables spellchecking for the search field in the rustdoc web interface.

As someone who uses Safari to browse through Rust docs, spellchecking gets really annoying.

src/librustdoc/html/layout.rs

@@ -83,6 +83,7 @@ pub fn render<T: fmt::Display, S: fmt::Display>(
             <div class=\"search-container\">\
                 <input class=\"search-input\" name=\"search\" \
                        autocomplete=\"off\" \
+                       spellcheck=\"false\" \
                        placeholder=\"Click or press ‘S’ to search, ‘?’ for more options…\" \
                        type=\"search\">\
                 <a id=\"settings-menu\" href=\"{root_path}settings.html\">\