Add git attributes

Author: dantleech

.gitattributes

@@ -0,0 +1,15 @@
+# Handle line endings automatically for files detected as text and leave all
+# files detected as binary untouched.
+* text=auto
+
+# Files and directories with the attribute export-ignore won’t be added to
+# archive files. See http://git-scm.com/docs/gitattributes for details.
+.gitattributes          export-ignore
+.gitignore              export-ignore
+/*.neon                 export-ignore
+/.github                export-ignore
+/.php-cs-fixer.dist.php export-ignore
+/doc/                   export-ignore
+/phpunit.*              export-ignore
+/phpstan.*              export-ignore
+/tests/                 export-ignore