runtime(java): Consent to HTML tags folding in Javadoc comments

HTML tags in Javadoc comments can additionally be folded
after applying
------------------------------------------------------------
	let g:html_syntax_folding = 1
	set foldmethod=syntax
------------------------------------------------------------

and giving explicit consent with
------------------------------------------------------------
	let g:java_consent_to_html_syntax_folding = 1
------------------------------------------------------------

Do not default to this kind of folding unless ALL start tags
and optional end tags are balanced in Javadoc comments;
otherwise, put up with creating runaway folds that break
syntax highlighting.

resolves: zzzyxwvut/java-vim#8.
closes: #17216

Signed-off-by: Aliaksei Budavei <0x000c70@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/doc/syntax.txt b/runtime/doc/syntax.txt
index a8fbe1a..ed72830 100644
--- a/runtime/doc/syntax.txt
+++ b/runtime/doc/syntax.txt
@@ -1,4 +1,4 @@
-*syntax.txt*	For Vim version 9.1.  Last change: 2025 Apr 19
+*syntax.txt*	For Vim version 9.1.  Last change: 2025 Apr 28
 
 
 		  VIM REFERENCE MANUAL	  by Bram Moolenaar
@@ -2175,6 +2175,13 @@
 line otherwise, with >
 	:let g:java_foldtext_show_first_or_second_line = 1
 
+HTML tags in Javadoc comments can additionally be folded by following the
+instructions listed under |html-folding| and giving explicit consent with >
+	:let g:java_consent_to_html_syntax_folding = 1
+Do not default to this kind of folding unless ALL start tags and optional end
+tags are balanced in Javadoc comments; otherwise, put up with creating runaway
+folds that break syntax highlighting.
+
 Trailing whitespace characters or a run of space characters before a tab
 character can be marked as an error with >
 	:let g:java_space_errors = 1