Add lua api links

Author: cwickham

docs/blog/posts/2025-10-06-1.8-release/index.qmd

@@ -117,7 +117,7 @@ execute_info["document-path"]
 
 ## Other Highlights
 
--  [Access metadata and variables in filters and shortcodes](): Use the new `quarto.variables.get()` and `quarto.metadata.get()` APIs.
+-  Access [metadata](/docs/extensions/lua-api.qmd#metadata-access) and [variables](/docs/extensions/lua-api.qmd#variables-access) in filters and shortcodes: Use the new `quarto.variables.get()` and `quarto.metadata.get()` APIs.
 
 - The default LaTeX engine is now `lualatex`.
 

docs/prerelease/1.8/_highlights.qmd

@@ -10,7 +10,7 @@ Quarto 1.8 includes the following new features:
 
 -  [Access execution settings from code cells](): Read the `QUARTO_EXECUTE_INFO` environment variable to access information about execution context.
 
--  [Access metadata and variables in filters and shortcodes](): Use the new `quarto.variables.get()` and `quarto.metadata.get()` APIs.
+-  Access [metadata](/docs/extensions/lua-api.qmd#metadata-access) and [variables](/docs/extensions/lua-api.qmd#variables-access) in filters and shortcodes: Use the new `quarto.variables.get()` and `quarto.metadata.get()` APIs.
 
 - The default LaTeX engine is now `lualatex`.