fix: quick error message improvement

Author: vkarpov15

lib/helpers/printJestWarning.js

@@ -7,13 +7,15 @@ if (typeof jest !== 'undefined' && !process.env.SUPPRESS_JEST_WARNINGS) {
     utils.warn('Mongoose: looks like you\'re trying to test a Mongoose app ' +
       'with Jest\'s default jsdom test environment. Please make sure you read ' +
       'Mongoose\'s docs on configuring Jest to test Node.js apps: ' +
-      'https://mongoosejs.com/docs/jest.html');
+      'https://mongoosejs.com/docs/jest.html. Set the SUPPRESS_JEST_WARNINGS to true ' +
+      'to hide this warning.');
   }
 
   if (setTimeout.clock != null && typeof setTimeout.clock.Date === 'function') {
     utils.warn('Mongoose: looks like you\'re trying to test a Mongoose app ' +
       'with Jest\'s mock timers enabled. Please make sure you read ' +
       'Mongoose\'s docs on configuring Jest to test Node.js apps: ' +
-      'https://mongoosejs.com/docs/jest.html');
+      'https://mongoosejs.com/docs/jest.html. Set the SUPPRESS_JEST_WARNINGS to true ' +
+      'to hide this warning.');
   }
 }