chore: add example env file, improve documentation and code comments

controllers/contactController.js

@@ -1,12 +1,10 @@
 // contactController.js
 module.exports = (pool, transporter) => {
     
-    // The main function that handles the form submission
     const submitForm = async (req, res) => {
         const { firstName, lastName, organization, email, phone, contactMethod, message } = req.body;
 
         try {
-            // 1. Save submission to the database
             const result = await pool.query(
                 `INSERT INTO submissions(first_name, last_name, organization, email, phone, contact_method, message) 
                  VALUES($1, $2, $3, $4, $5, $6, $7) RETURNING *`,
@@ -15,7 +13,6 @@ module.exports = (pool, transporter) => {
 
             console.log('Successfully saved submission to the database:', result.rows[0]);
 
-            // 2. Send the email notification
             const mailOptions = {
                 from: `"Contact Form" <contact@dlseitz.dev>`,
                 to: process.env.EMAIL_RCPT,