fix: added pandoc for building docs in CI (#123)

* added pandoc install to CI

.github/workflows/CI.yml

@@ -12,6 +12,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v3
+      - name: Install apt-get dependencies
+        run: |
+          sudo apt-get update
+          sudo apt-get -qq install pandoc
       - name: Build docs with sphinx
         run: |
           pip install -r docs/requirements.txt