Add some reST to the news entry

Author: brettcannon

Misc/NEWS.d/next/Build/2026-01-16-14-27-53.gh-issue-143941.TiaE-3.rst

@@ -1,2 +1,2 @@
-Move WASI-related files to Platforms/WASI. Along the way, leave a deprecated
-Tools/wasm/wasi/__main__.py behind for backwards-compatibility.
+Move WASI-related files to :file:`Platforms/WASI`. Along the way, leave a
+deprecated Tools/wasm/wasi/__main__.py behind for backwards-compatibility.