[Wordpress] script to include template from any location

template-includer.php

<?php function register_project_templates(){

			//Create the key used for the themes cache
			$cache_key = 'page_templates-'.md5( get_theme_root().'/'.get_stylesheet());

			$templates = wp_get_theme()->get_page_templates();

			if( empty( $templates ) ) {

				$templates = array();

			}

			wp_cache_delete($cache_key, 'themes');

                        //template file absolute path
			$loc_tem = dirname(__FILE__).'/template-locations.php';

			$location_template = array( $loc_tem => 'Template Title');

			$templates = array_merge($templates, $location_template);

			//Add the modified cache to allow wordpress to pick it up for listing available templates
			wp_cache_add( $cache_key, $templates, 'themes', 1800 );

		}
?>