Delete sub files (#17400)

Fixes #17214

Summary of the issue:
#17214 changed the method of building html documents. Many .md.sub files will be generated in the process. These files are incorrectly included in the installer, increasing the installer size by about 2MB. After installing NVDA, it takes up an additional 30MB of space.

source/setup.py

@@ -287,6 +287,7 @@ def _genManifestTemplate(shouldHaveUIAccess: bool) -> tuple[int, int, bytes]:
 			+ (
 				"__pycache__",
 				"*.md",
+				"*.md.sub",
 				"*.xliff",
 				"*/user_docs/styles.css",
 				"*/user_docs/numberedHeadings.css",