add linefeed check action

Author: jmckenna

.github/workflows/check-crlf.yml

@@ -17,4 +17,4 @@ jobs:
       - name: Use action to check for CRLF endings
         uses: erclu/[email protected]
         with: # ignore directories containing *.csv & data
-          exclude: /demo/
+          exclude: /demo/ /ms4w/ /test/ Makefile.vc