Merge pull request #41 from sebastianbergmann/main

Exclude non-essential / superfluous files from export

Author: shyim

.gitattributes

@@ -0,0 +1,7 @@
+/.github                export-ignore
+/tests                  export-ignore
+/.gitattributes         export-ignore
+/.gitignore             export-ignore
+/.php-cs-fixer.dist.php export-ignore
+/phpstan.neon.dist      export-ignore
+/phpunit.xml.dist       export-ignore