feature(core): plugin template changes

.editorconfig

.env.testing

.gitignore

.gitlab-ci.yml

.wordpress-org/.gitkeep

assets-src/js/app.js

assets-src/scss/app.scss

codeception.dist.yml

composer.json

composer.lock

lang/.gitignore

lang/pl_PL.po

package-lock.json

package.json

phpcs.xml.dist

phpstan.neon.dist

phpunit-integration.xml

phpunit-unit.xml

plugin-template.php

scoper.inc.php