onMatch method
Processes match, adding nodes to parser and possibly advancing
parser.
Returns whether the caller should advance parser by match[0].length.
Implementation
@override
bool onMatch(InlineParser parser, Match match) {
final chars = match.match;
String text;
if ('&"<>'.contains(match[1]!) && parser.encodeHtml) {
text = escapeHtml(match[1]!);
} else {
text = chars[1];
}
parser.addNode(Text(text));
return true;
}