MarkText index.js getRecommendTitleFromMarkdownString redos

A vulnerability has been found in MarkText up to 0.17.1 and classified as problematic. Affected by this vulnerability is the function getRecommendTitleFromMarkdownString of the file marktext/src/main/utils/index.js. The manipulation leads to inefficient regular expression complexity. The attack can be launched remotely. The exploit has been disclosed to the public and may be used.