Update .gitattributes (twbs#30934)

This requires git >= 2.10 but it was released almost 4 years ago.

.gitattributes

@@ -1,18 +1,8 @@
 # Enforce Unix newlines
-*.css   text eol=lf
-*.html  text eol=lf
-*.js    text eol=lf
-*.json  text eol=lf
-*.md    text eol=lf
-*.scss  text eol=lf
-*.sh    text eol=lf
-*.svg   text eol=lf
-*.txt   text eol=lf
-*.xml   text eol=lf
-*.yml   text eol=lf
+* text=auto eol=lf
 
 # Don't diff or textually merge source maps
-*.map   binary
+*.map binary
 
 bootstrap.css linguist-vendored=false
 bootstrap.js linguist-vendored=false