Upgrade pmndrs/docs workflow to version 3

Updated workflow to use build.yml version 3 and added docker_tag.

Author: abernier

.github/workflows/docs.yml

@@ -11,8 +11,9 @@ concurrency:
 
 jobs:
   build:
-    uses: pmndrs/docs/.github/workflows/build.yml@v2
+    uses: pmndrs/docs/.github/workflows/build.yml@v3
     with:
+      docker_tag: '3'
       mdx: 'docs'
       libname: 'React Three Fiber'
       libname_short: 'r3f'