Add doc step to ci

.github/workflows/ci.yml

@@ -88,4 +88,15 @@ jobs:
         with:
           coverage-files: ./lcov.info
           minimum-coverage: 100 # Set coverage threshold.
-
+   docs:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+
+      - name: Install Foundry
+        uses: foundry-rs/foundry-toolchain@v1
+
+      - name: Build documentation
+        run: |
+          forge --version
+          forge doc