[Maintenance] Commit .bat files with LF line endings, but check out as CRLF

Windows 9x requires CRLF for batch files to work at all. While Windows
XP and later appear to work with LF line endings, they introduce
devious glitches with certain commands:

	https://www.dostips.com/forum/viewtopic.php?t=8988

However, we still want to use LF endings in the repo to prevent the
annoying ^M whitespace errors.

Part of P0002, funded by GhostPhanom.

.gitattributes

@@ -1,4 +1,5 @@
 *.asm text eol=crlf
+*.bat text eol=crlf
 *.[ch]* text eol=lf
 *.mak text eol=lf
 zuncom/zun*.txt -text