feat: add typecheck to pr build workflow (#202)

.github/workflows/pr.yml

@@ -38,6 +38,9 @@ jobs:
           restore-keys: |
             ${{ runner.os }}-docusaurus-en-${{ hashFiles('**/yarn.lock') }}
 
+      - name: Typecheck
+        run: yarn typecheck
+
       - name: Build website
         run: yarn build --locale en
         env: