gitattributes: note that png and jpg are binary files
the assets/*.png files were getting CRLF'd up during rebases
# Auto detect text and normalize to LF on commit regardless of "core.autocrlf".
# See: https://help.github.com/en/articles/dealing-with-line-endings#example
* text=auto eol=lf
+
+# Denote all files that are truly binary and should not be modified.
+*.png binary
+*.jpg binary
