docs(lua-api): Add Typst path function to lua-api documentation

Related to:

- quarto-dev/quarto-cli#13762

(cherry picked from commit 7fe9893)

Author: mcanouil

docs/extensions/lua-api.qmd

@@ -257,6 +257,7 @@ Quarto exposes paths to utilities that are likely to be useful to Lua extension
 |------------------------------------|------------------------------------|
 | `quarto.paths.rscript()` | Returns the path to `Rscript` that Quarto uses in the `knitr` engine and R files for `quarto run` scripts |
 | `quarto.paths.tinytex_bin_dir()` | Returns the path to `TinyTeX` binaries directory (where `tlmgr`, `pdlatex` and others are). If Quarto did not install `TinyTeX` and does not found it, it will return `nil`. This means that PDF rendering by Quarto probably used tools found in PATH. |
+| `quarto.paths.typst()` | Returns the path to Typst used by Quarto. |
 
 ### Shortcodes