doc: fix case error of eol attribute in example

The eol attribute only accepts "crlf" and "lf",
but the example incorrectly capitalizes "crlf".

References:

- https://git-scm.com/docs/gitattributes#_eol
- https://github.com/git/git/blob/v2.45.2/convert.c#L1278

Signed-off-by: Shane Sun <github@waterlemons2k.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/Documentation/gitattributes.txt b/Documentation/gitattributes.txt
index 4338d02..4370175 100644
--- a/Documentation/gitattributes.txt
+++ b/Documentation/gitattributes.txt
@@ -374,7 +374,7 @@
 attribute is used to avoid ambiguity.
 
 ------------------------
-*.ps1		text working-tree-encoding=UTF-16LE eol=CRLF
+*.ps1		text working-tree-encoding=UTF-16LE eol=crlf
 ------------------------
 
 You can get a list of all available encodings on your platform with the