Update meta description to mention Amazon Prime Games support (#18)

This matches the homepage text.

Author: Calinou

pages/cla.tsx

@@ -12,7 +12,7 @@ const Cla: NextPage = () => {
         <title>CLA</title>
         <meta
           name="description"
-          content="An Open Source GOG and Epic Games Launcher"
+          content="An Open Source Epic, GOG and Amazon Prime Games Launcher"
         />
         <link rel="icon" href="/favicon.ico" />
       </Head>

pages/donate.tsx

@@ -9,7 +9,7 @@ const Donate: NextPage = () => {
         <title>Support Heroic Development</title>
         <meta
           name="description"
-          content="An Open Source GOG and Epic Games Launcher"
+          content="An Open Source Epic, GOG and Amazon Prime Games Launcher"
         />
         <link rel="icon" href="/favicon.ico" />
       </Head>

pages/index.tsx

@@ -28,7 +28,7 @@ const Home: NextPage = () => {
         <title>Heroic Games Launcher</title>
         <meta
           name="description"
-          content="An Open Source GOG and Epic Games Launcher"
+          content="An Open Source Epic, GOG and Amazon Prime Games Launcher"
         />
         <link rel="icon" href="/favicon.ico" />
       </Head>