chore: Update .gitattributes for saving space (and trees).

.gitattributes

@@ -1,11 +1,22 @@
+/.github export-ignore
+/build export-ignore
+/docker export-ignore
+/docs export-ignore
 /spec export-ignore
+/tests export-ignore
+.auto-changelog export-ignore
 .editorconfig export-ignore
 .gitattributes export-ignore
 .gitignore export-ignore
+.php-cs-fixer.dist.php export-ignore
 .scrutinizer.yml export-ignore
-phpunit.xml.dist export-ignore
-infection.json.dist export-ignore
-grumphp.yml.dist export-ignore
-phpspec.yml.dist export-ignore
-/docker export-ignore
-docker-composer.yaml export-ignore
+infection.json export-ignore
+grumphp.yml export-ignore
+phpspec.yml export-ignore
+docker-compose.yaml export-ignore
+psalm-baseline.xml export-ignore
+psalm.xml export-ignore
+phpstan-baseline.neon export-ignore
+phpstan-docs-baseline.neon export-ignore
+phpstan-unsupported-baseline.neon export-ignore
+phpstan.neon.dist export-ignore