Feat: Add .gitattributes (#22)

Author: simPod

.gitattributes

@@ -0,0 +1,12 @@
+# Set the default behavior, in case people don't have core.autocrlf set.
+* text eol=lf
+/.gitattributes export-ignore
+/.gitignore export-ignore
+/.github export-ignore
+/phpcs.xml.dist export-ignore
+/phpstan.neon.dist export-ignore
+/phpstan-baseline.neon export-ignore
+/phpunit.xml.dist export-ignore
+/psalm.xml.dist export-ignore
+/psalm-baseline.xml export-ignore
+/tests export-ignore