chore: update sponsors (vuejs#2323)

Author: vue-bot

themes/vue/_config.yml

@@ -10,10 +10,6 @@ special_sponsors:
     img: stdlib.png
     description: 'Build APIs you need in minutes instead of days, for free.'
 platinum_sponsors:
-  - url: >-
-      https://bit.dev/?utm_source=vue&utm_medium=vue&utm_campaign=vue&utm_term=vue&utm_content=vue
-    img: bit.png
-    name: Bit
   - url: >-
       https://vueschool.io/?utm_source=Vuejs.org&utm_medium=Banner&utm_campaign=Sponsored%20Banner&utm_content=V1
     img: vueschool.png
@@ -120,6 +116,9 @@ silver_sponsors:
   - url: 'https://dopamine.bg/'
     img: dopamine.png
     name: Dopamine
+  - url: 'https://roadster.com'
+    img: roadster.png
+    name: Roadster
 bronze_sponsors:
   - url: 'https://www.accelebrate.com/'
     img: accelebrate.png