typo in docbloc of export_wp()

[pbiron]

There's a typo in the @param hash of ​export_wp() that causes the DevHub page to format incorrectly.

There is a missing ` in the description of $args['category'] that causes the remainder of the @param hash to wrapped in <code>.

At first I thought this was another case like ​incorrect parsing of markdown in @param blocks, but then realized it was just a typo in the docbloc.

[pbiron]

patch

[pbiron]

screenshot from Code Reference

[SergeyBiryukov]

In 40958:

Docs: Add missing backtick character in export_wp() DocBlock.

Props pbiron.
Fixes #41178.