Add man pages into CI

.github/workflows/pull_request.yml

@@ -7,7 +7,15 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v1
-    - uses: ammaraskar/sphinx-action@master
+    - name: Prepare
+      run: |
+        sudo apt-get update -y
+        sudo apt-get install -y git python3-pip mandoc
+        pip install -r docs/requirements.txt
+    - name: Gen_man_pages
+      run: make man
+    - name: Gen_sphinx
+      uses: ammaraskar/sphinx-action@master
       with:
-        pre-build-command: "apt-get update -y && apt-get install -y git python3-pip && pip install -r docs/requirements.txt"
+        pre-build-command: "apt-get update -y && apt-get install -y git"
         docs-folder: "docs/"