[css-ruby] Add inline issue about katatsuki ruby

Author: frivoal

css-ruby-1/Overview.bs

@@ -1316,6 +1316,21 @@ Ruby Text Distribution: the 'ruby-align' property</h3>
 				     src="images/ra-l-rb.gif" >
 				<p class="caption">''ruby-align/start'' ruby distribution
 			</div>
+
+			ISSUE: "Katatsuki ruby" (肩付きルビ) is close to,
+			but not quite the same as,
+			this ''ruby-align/start'' value.
+			In particular,
+			its behavior when overhanging its base
+			can differ from start alignment
+			depending on surrounding context,
+			see <a href="https://www.w3.org/TR/jlreq/#positioning_of_monoruby_with_respect_to_base_characters">JLREQ</a>.
+			Also, it's only ever used in vertical writing,
+			and the JLTF considers it not particularly important,
+			so it may not be worth the effort to make this value smart enough to deal with katatsuki ruby.
+			If ''ruby-align/start'' is needed for some other purpose,
+			we should keep it.
+			Otherwise, maybe just drop it?
 		</dd>
 
 		<dt><dfn>center</dfn></dt>