Add latex manual CI job.

.github/workflows/latex.yml

@@ -0,0 +1,28 @@
+name: Build manual
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Fix stupidity
+      run: |
+        cp AUTHORS AUTHORS.
+        cp LICENSE LICENSE.
+    - name: Compile LaTeX
+      uses: xu-cheng/latex-action@v2
+      with:
+        working_directory: manual
+        root_file: tracy.tex
+    - uses: actions/upload-artifact@v2
+      with:
+        name: manual
+        path: manual/tracy.pdf