Update contributors count

Author: mkurz

app/views/getInvolved.scala.html

@@ -20,7 +20,7 @@ <h1>How you can help</h1>
             <div class="links">
 
                 <h3 class="opencollective">Donate to our Open Collective</h3>
-                <a href="//opencollective.com/playframework#section-contributors">75+ backers</a>
+                <a href="//opencollective.com/playframework#section-contributors">300+ backers</a>
                 <p>
                     Play uses <a href="//opencollective.com/playframework">Open Collective</a> to collect donations from sponsors. These funds are used to pay contributors and cover project costs, openly and transparently.
                     Individuals and companies alike can support Play financially by <a href="@routes.Application.sponsors">becoming backers or premium sponsors</a>.