8 – How do I create an alias for the node edit page?

Use a src/Routing/RouteSubscriber.php file in your module.

namespace DrupalexampleRouting;

use DrupalCoreRoutingRouteSubscriberBase;
use SymfonyComponentRoutingRouteCollection;

/**
 * Listens to the dynamic route events.
 */
class RouteSubscriber extends RouteSubscriberBase {

  /**
   * {@inheritdoc}
   */
  protected function alterRoutes(RouteCollection $collection) {
    if ($route = $collection->get('entity.node.edit_form')) {
      $route->setPath('/project/{node}/edit');
    }
  }

}

Use a example.services.yml file in your module (if the module is named example).

services:
  example.route_subscriber:
    class: DrupalexampleRoutingRouteSubscriber
    tags:
      - { name: event_subscriber }

https://www.drupal.org/docs/8/api/routing-system/altering-existing-routes-and-adding-new-routes-based-on-dynamic-ones