Provide way to reset `Paper` instance

The current way RankMath is coded is heavily coupled with the current request URI, making the plugin almost impossible to extend or use in API contexts.

A big part of that is due to the reliance on the RankMath\Paper\Paper class, which initializes into its own private static $instance.

While it would take a major refactor to make the plugin more modular, a good bulk of the issues can be solved easily and _in a non-breaking manner_ by simply adding the following method to the class:

<?php // includes/frontend/paper/class-paper.php
/**
 * Clears and reinitializes the object.
 */
public static function reset() {
	self::$instance = null;
	return self::get();
}

This could then be used to do the following (just one of a dozen examples. I’m trying to implement a free WPGraphQL API)

<?php
// Use RankMath generated description (with settings fallback and replacements) in a custom card loop:
...
foreach( $wp_posts as $posts ) {
	setup_postdata( $post );
	\RankMath\Paper\Paper::reset();
        ...
        <div class="excerpt"> <?php echo \RankMath\Paper\Paper::get()->get_description(); ?></div>
	...
}

I really hope you consider adding this to the plugin.

PS: It seems your github repo is no longer in use. Is there another way for devs to contribute in the spirit of open source?