Prep Plugin for release on WordPress.org (#23)

* Update translation text domain
* Escape everything that should be escaped.
* Add nonce checks where needed.
* Sanitize all inputs.
* Apply Code style changes across the codebase.
* Correct many deprecation notices.
* Optimize load order of many filters.
* Add Proper Build script
* Use emojii flags
* Fix i18n deprecation  notice for translating too early
* Put all scripts in footer and load async

inc/database/engine/class-table.php

@@ -51,7 +51,7 @@ abstract class Table extends \BerlinDB\Database\Table {
 			return false;
 		}
 
-        return (bool) is_main_site();
+		return (bool) is_main_site();
 	}
 
 	/**