Setup (with default key) (#1)

* add ximera.cls

* prepare action

* action: fix key

* action fix courses

* use temporary default key

* Update Readme

Author: wiobber

.devcontainer/devcontainer.json

@@ -0,0 +1,74 @@
+name: Ximera Workflow
+
+on:
+  push:    
+    branches:
+        - 'main'
+
+jobs:
+  build-ximera:
+    name: Build and preview Ximera Courses
+    runs-on: ubuntu-latest
+
+    permissions:
+      actions: read
+      contents: read
+      packages: write
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0   # full 
+
+      - name: Setup cache
+        uses: actions/cache@v4
+        with:
+          path: | 
+            **/*.html
+            **/*.pdf
+            **/*.svg
+            **/*.aux
+            **/*.xref
+            **/*.toc
+            !xmPictures/**
+            !.git/**
+            !.github/**
+          key: ximera-${{ github.ref_name }}-${{ github.sha }}
+          restore-keys: |
+            ximera-${{ github.ref_name }}-
+            ximera-
+
+
+      - name: Build and publish Ximera courses
+        env:
+          ### Use .xmKeyfile for test/demo
+          # GPG_KEY: ${{ secrets.GPG_KEY }}
+          # GPG_KEY_ID: ${{ secrets.GPG_KEY_ID }}
+          XIMERA_URL: "https://xerxes.ximera.org/"
+          XIMERA_NAME: ${{ github.repository_owner }}-${{ github.event.repository.name }}
+          XM_COMPILE_SEQUENCE: "html,handout.pdf"
+          # XIMERA_NAME: ${{ vars.XIMERA_NAME }}*${{ github.ref_name }}
+          # XIMERA_NAME: ${{ github.repository_owner }}-${{ github.event.repository.name }}-${{ github.ref_name }}
+        run: |
+          ls -alrt
+          chmod +x xmScripts/xmlatex
+          rm -rf ximera-downloads/with-answers
+          # git config --global http.postBuffer 524288000
+          # git config --global core.compression 9
+          ./xmScripts/xmlatex bake  -j 5 
+          ./xmScripts/xmlatex frost 
+          ./xmScripts/xmlatex name  
+          ./xmScripts/xmlatex serve 
+          # ./xmScripts/xmlatex ghaction
+          echo "✅ Published to $XIMERA_URL$XIMERA_NAME " >> $GITHUB_STEP_SUMMARY
+
+      - name: Setup ximera serve cache (only .git)
+        id: serve-cache
+        uses: actions/cache/save@v4
+        with:
+          path: | 
+            xmScripts/**
+            .git/**
+          key: ximeraSERVE-${{ github.ref_name }}-${{ github.sha }}
+