docs: Consistent position wordings [skip ci]

docs/pages/index.mdx

@@ -67,14 +67,14 @@ import UserTestimonial from 'components/UserTestimonial';
     <div className="flex flex-col gap-6">
       <UserTestimonial
         userName="Kieran McHugh"
-        position="Founder & CEO at Daybridge"
+        position="Founder & CEO of Daybridge"
         quote="We were initially worried that adding support for multiple languages to our app would add overwhelming complexity, but next-intl genuinely made the process so much smoother than we expected."
         portraitUrl="/user-kieran-mchugh.jpg"
         href="https://twitter.com/kieranmch"
       />
       <UserTestimonial
         userName="Colin Sidoti"
-        position="Co-founder & CEO at Clerk"
+        position="Co-founder & CEO of Clerk"
         quote="Interop with next-intl was a design requirement"
         portraitUrl="/user-colin-sidoti.jpg"
         href="https://twitter.com/tweetsbycolin/status/1654418495646629888"
@@ -83,14 +83,14 @@ import UserTestimonial from 'components/UserTestimonial';
     <div className="flex flex-col gap-6">
       <UserTestimonial
         userName="Cali Castle"
-        position="Founder & CEO at Zolplay"
+        position="Founder & CEO of Zolplay"
         quote="I think next-intl should become a Next.js first-class citizen at some point, it’s just brilliant and simple to use."
         portraitUrl="/user-cali-castle.png"
         href="https://twitter.com/thecalicastle/status/1638566769433669633"
       />
       <UserTestimonial
         userName="Alvar Lagerlöf"
-        position="Senior Frontend Developer at Matsmart"
+        position="Senior Frontend Developer at Motatos"
         quote="It's a great tool. We're using it now for our App Router rollout."
         portraitUrl="/user-alvar-lagerlof.jpeg"
         href="https://twitter.com/alvarlagerlof"