Add CI pipeline job to check syntax with rstcheck

.github/workflows/ci.yml

@@ -6,6 +6,22 @@ on:
   pull_request:
 
 jobs:
+  syntax-check:
+    name: Check syntax
+    runs-on: ubuntu-latest
+    container: python:3.11-slim
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v3
+      - name: Create virtual environment
+        run: |
+          python -m venv venv
+          . venv/bin/activate
+          pip install -r requirements.txt
+      - name: Syntax check
+        run: |
+          . venv/bin/activate
+          rstcheck --recursive --ignore-directives "tabs" fido2/ hsm/ nethsm/ nextbox/ nitrokey3/ nitropad/ nitropc/ nitrophone/ nitrowall/ pro/ software/ start/ storage/ u2f/
   build-error-check:
     name: Check build error
     runs-on: ubuntu-latest

.rstcheck.cfg

@@ -0,0 +1,2 @@
+[rstcheck]
+ignore_directives=tabs

requirements.txt

@@ -12,6 +12,7 @@ MarkupSafe==2.1.2
 packaging==23.1
 Pygments==2.15.1
 requests==2.30.0
+rstcheck==6.2.0
 snowballstemmer==2.2.0
 soupsieve==2.4.1
 Sphinx==6.2.1