Add description to message body of Verify Email form

Made the required changes.
Kindly review and merge :)

Thanks for working on this. Some change to the text is needed. In particular, it needs to reference the available token.

Hi @lostcarpark, please take a look at the changes.

Sorry to be picky, but I think the description could be a tiny bit clearer.

Also, sorry for not including in the original request, but I think we should have a test case for this. This can be added in VerifyEmailSetupTest.php, in the testVerifyEmailConfig function, just before submitting the form. Add the following assertion:

$this->assertSession()->elementExists('xpath', '//div[@id="edit-email-body--description"][contains(text(), "Email message to be sent to user. Place token [verify-email:url] to insert the login link")]');

I promise this is the last change!

That looks perfect now, and all tests are passing.

Moving to RTBC.

@lavanyatalwar, thank you for working on this issue, and thanks for your patience with my nit-picking.

Merge completed, moving to fixed.

That looks perfect now, and all tests are passing.

Moving to RTBC.