v0.2.0
Support custom title text for callouts
https://oprypin.github.io/markdown-callouts/#custom-titles
NOTE: **This is used as the title.** Lorem ipsum dolor sit amet, consectetur
adipiscing elit. Nulla et euismod nulla. Curabitur feugiat, tortor non
consequat finibus, justo purus auctor massa, nec semper lorem quam in massa.