Make markdown parser more safe (#4105)

Fixes #3722

lib/std/special/docs/main.js

@@ -1432,7 +1432,7 @@
                     line.type = "ul";
                     line.text = line.text.substr(1);
                 }
-                else if (line.text.match(/\d+\./)) {
+                else if (line.text.match(/^\d+\..*$/)) { // if line starts with {number}{dot}
                     const match = line.text.match(/(\d+)\./);
                     line.type = "ul";
                     line.text = line.text.substr(match[0].length);