Add [true] [false] and [null] tags to class reference

editor/editor_help.cpp

@@ -2616,6 +2616,25 @@ static void _add_text_to_rt(const String &p_bbcode, RichTextLabel *p_rt, const C
 			p_rt->pop(); // font
 
 			pos = brk_end + 1;
+
+		} else if (tag == "true" || tag == "false" || tag == "null") {
+			// Use monospace font with darkened background color to make code easier to distinguish from other text.
+			String link_target = (tag == null ? "Variant" : "bool" );
+
+			p_rt->push_font(doc_bold_font);
+			p_rt->push_font_size(doc_code_font_size);
+			p_rt->push_bgcolor(code_bg_color);
+			p_rt->push_color(code_color.lerp(p_owner_node->get_theme_color(SNAME("error_color"), EditorStringName(Editor)), 0.6));
+			p_rt->push_meta("@class " + link_target, underline_mode);
+
+			p_rt->add_text(tag);
+
+			p_rt->pop(); // color
+			p_rt->pop(); // bgcolor
+			p_rt->pop(); // font_size
+			p_rt->pop(); // font
+
+			pos += (tag == "false" ? 5 : 4); // `len("false")` and `len("true")`.
 		} else if (tag == "b") {
 			// Use bold font.
 			p_rt->push_font(doc_bold_font);