LibWeb: Parse "br" end tags during "in body"

Author: https://github.com/kylemclean
Commit: 1ad81e4833
Pull-request: https://github.com/SerenityOS/serenity/pull/2491

Libraries/LibWeb/Parser/HTMLDocumentParser.cpp

@@ -1195,10 +1195,12 @@ void HTMLDocumentParser::handle_in_body(HTMLToken& token)
     }
 
     if (token.is_end_tag() && token.tag_name() == "br") {
-        TODO();
+        token.drop_attributes();
+        goto BRStartTag;
     }
 
     if (token.is_start_tag() && token.tag_name().is_one_of("area", "br", "embed", "img", "keygen", "wbr")) {
+    BRStartTag:
         reconstruct_the_active_formatting_elements();
         insert_html_element(token);
         m_stack_of_open_elements.pop();