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

data/translatable-strings.php

@@ -10,12 +10,12 @@
 defined('ABSPATH') || exit;
 
 return [
-	'day'    => __('day', 'wp-ultimo'),
-	'days'   => __('days', 'wp-ultimo'),
-	'week'   => __('week', 'wp-ultimo'),
-	'weeks'  => __('weeks', 'wp-ultimo'),
-	'month'  => __('month', 'wp-ultimo'),
-	'months' => __('months', 'wp-ultimo'),
-	'year'   => __('year', 'wp-ultimo'),
-	'years'  => __('years', 'wp-ultimo'),
+	'day'    => __('day', 'wp-multisite-waas'),
+	'days'   => __('days', 'wp-multisite-waas'),
+	'week'   => __('week', 'wp-multisite-waas'),
+	'weeks'  => __('weeks', 'wp-multisite-waas'),
+	'month'  => __('month', 'wp-multisite-waas'),
+	'months' => __('months', 'wp-multisite-waas'),
+	'year'   => __('year', 'wp-multisite-waas'),
+	'years'  => __('years', 'wp-multisite-waas'),
 ];