Add latex build check to PRs (#37)

* Add release workflow

* Create validate.yml

* Update validate.yml

.github/workflows/validate.yml

@@ -0,0 +1,23 @@
+name: Validate LaTeX Document
+on:
+  pull_request:
+    branches:
+      - main
+jobs:
+  build_latex:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Set up Git repository
+        uses: actions/checkout@v3
+      - name: Build book
+        uses: xu-cheng/texlive-action/full@v1
+        with:
+          run: |
+            apk add make
+            cd book
+            make all
+      - name: Upload PDF
+        uses: actions/upload-artifact@v3
+        with:
+          name: PDF
+          path: book/book.pdf