docs: Add Supabase (#307)

Adds Supabase to https://swc.rs/docs/customers

We use it extensively in [Supabase](https://supabase.com/), including
private repositories that won't show up on [this
search](https://github.com/search?q=org%3Asupabase%20%22%40swc%2F%22&type=code).

🫶

P.S.: In https://supabase.com/brand-assets, you can find other assets,
but to ensure our logo shows up correctly regardless of the system theme
(dark/light), I opted to use just the logo.

Author: raulb

apps/website/customers.json

@@ -148,5 +148,11 @@
     "image": "/img/customers/evershop.png",
     "infoLink": "https://evershop.io/",
     "width": 110
+  },
+  {
+    "caption": "Supabase",
+    "image": "/img/customers/supabase.png",
+    "infoLink": "https://supabase.com/",
+    "width": 128
   }
 ]