Better text for letter of invitation

Author: Helio Loureiro

index.html

@@ -580,7 +580,7 @@ <h2>We're Passionate About Python and the Community</h2>
                     <h2>Letter of invitation</h2>
                 </div>
                 <div>
-                    <p>Here is the letter of invitation template:</p>
+                    <p>Here is the letter of invitation template in case you require one for visa request:</p>
                     <p align="center">
                         <a href="Letter_of_invitation-template.pdf">
                             Letter_of_invitation-template.pdf