adding missing .gitattributes file

.gitattributes

@@ -0,0 +1,23 @@
+# enforce unix style line endings
+*.ts text eol=lf
+*.tsx text eol=lf
+*.md text eol=lf
+*.txt text eol=lf
+*.js text eol=lf
+*.json text eol=lf
+*.xml text eol=lf
+*.svg text eol=lf
+*.yaml text eol=lf
+*.css text eol=lf
+*.html text eol=lf
+*.py text eol=lf
+*.exp text eol=lf
+*.manifest text eol=lf
+
+# do not enforce text for everything - it causes issues with random binary files
+
+*.sln text eol=crlf
+
+*.png binary
+*.jpg binary
+*.jpeg binary