Update README.md

README.md now has been improved with more details.

PHP Projects/User_Signup_Login_with_database/README.md

@@ -17,11 +17,15 @@ logout.php - Destroys the current session and redirects back to index.php
 
 database.php - Contains the required credentials to connect to the database.  
 
-forgot-password.php - It asks for the email that is present in the database from the user. If email exists in the database, it generates an ***unique token*** and sets expiry time as 30 minutes from the time it was generated. Then, the token is sent via email (using PHP mailer) to the user. The user has to reset the password in 30 minutes, or else the token becomes invalid.
+forgot-password.php - It asks for the email that is present in the database from the user. If email exists in the database, it generates an ***unique token*** and sets expiry time as 30 minutes from the time it was generated. Then, the token is sent via email (using PHP Mailer) to the user. The user has to reset the password in 30 minutes, or else the token becomes invalid.
 
-mailer.php - Contains the required SMTP credentials to send email to the user.
+mailer.php - Contains the required SMTP credentials to send email to the user. Similar to a web server, a mail server sends emails. Thus, to send emails to the user, you need valid SMTP credentials. There are many free SMTP providers, use any one of them and accordingly change the credentials in this file.
 
 reset-password.php - If the token is valid, and is used before the time limit, the user is shown a page to reset the password. Else, the user is redirected to the forgot-password page where he/she can request a new token for the same. If everything including password requirements are fullfiled, the password is updated in the database.
+
+### PHP Mailer
+PHP Mailer is an email sending library for PHP. PHP supports sending emails via mail() function, but configuration might be tedious. PHP Mailer makes the whole process easy. PHP Mailer must be installed the project directory using Composer (PHP dependency manager). Kindly refer to the repository of the PHP Mailer for the same.  
+Repo Link: https://github.com/PHPMailer/PHPMailer
 
 # How to run the project?
 * You need to install PHP. For that, you can install XAMPP.