Add default gitattributes file.

Author: Crell

.gitattributes

@@ -0,0 +1,21 @@
+# Path-based git attributes
+# https://www.kernel.org/pub/software/scm/git/docs/gitattributes.html
+
+# Ignore all test and documentation with "export-ignore".
+/.gitattributes     export-ignore
+/.gitignore         export-ignore
+/.travis.yml        export-ignore
+/.github            export-ignore
+/.editorconfig      export-ignore
+/default-.env       export-ignore
+/Taskfile           export-ignore
+/phpstan.neon.dist  export-ignore
+/phpunit.xml.dist   export-ignore
+/.scrutinizer.yml   export-ignore
+/tests              export-ignore
+/docs               export-ignore
+/phpdocker          export-ignore
+/benchmarks         export-ignore
+/docker-compose.yml export-ignore
+/phpbench.json      export-ignore
+/profile.php        export-ignore