Broken links to "Module pandoc.text" section in lua-filters documentation

[refashioned]

There are two links to the "Module pandoc.text" section that don't work. The links are using the anchor module-text, but the anchor is actually module-pandoc.text.

pandoc/doc/lua-filters.md

Line 388 in 226f765

functions defined in the [`text` module](#module-text) to the

pandoc/doc/lua-filters.md

Line 477 in 226f765

Use the [pandoc.text](#module-text) module for Unicode-aware

[tarleb]

Thanks! A PR for that would be most welcome.