Details:
Extra tags to be treated as inline tags.
By default, only standard HTML inline elements will be treated as inline tags (excluding Vue built-in special elements).
All other unknown elements will be treated as block tags, because we are assuming that they are custom Vue components.
Treating Vue components as block tags would work as expected in most cases. However, in some edge cases, the behavior of block tags is not ideal with Vue components. For example, when using a HTML block tag at the beginning of a list item, the following Markdown syntax in the same list item will be invalid, but users might want an inline Vue component there.
You can use this option to specify unknown tags as inline tags.
Notice that this option is case-sensitive, and has lower priority than the blockTags option.