[css-ui-3] Bikeshed disambiguation

Author: frivoal

css-ui/Overview.bs

@@ -26,6 +26,8 @@ Link Defaults: css21 (property) min-width
 Link Defaults: css21 (property) min-height
 Link Defaults: css21 (property) max-width
 Link Defaults: css21 (property) max-height
+Link Defaults: css-writing-modes-3 (dfn) start
+Link Defaults: css-writing-modes-3 (dfn) end
 Ignored Terms: outline-top
 Ignored Terms: outline-left
 Ignored Terms: ime-mode