feat(contact-us): add customizable button text and center button content

Pass `buttonText="Submit request"` prop to ContactUsForm on contact page. Enhance button styles with flexbox centering for better alignment of text and loading spinner.

app/(home)/contact-us/page.tsx

@@ -39,7 +39,7 @@ const ContactUsPage = () => {
       </div>
       <div className="flex flex-col items-center mt-16 px-8 ">
         <section className="border border-gray-300 rounded-4xl w-full lg:max-w-2/3 flex flex-col items-center bg-white">
-          <ContactUsForm columnsPerRow={1} />
+          <ContactUsForm columnsPerRow={1} buttonText="Submit request"/>
         </section>
       </div>
     </main>

app/_contact-us/form.tsx

@@ -144,7 +144,7 @@ const ContactUsForm = ({
         }}
       />
       <div className={`${colSpanClass} flex justify-end`}>
-        <button className="bg-(--primary) cursor-pointer w-fit text-white rounded-full py-4 px-6">
+        <button className="bg-(--primary) cursor-pointer w-fit text-white rounded-full py-4 px-6 flex justify-center items-center text-center">
           {isLoading ? <Loading /> : buttonText}
         </button>
       </div>