New github workflow: git pull & commit from the web server

[gwynforthewyn]

A workflow is needed to simply do some ssh-adding and a git pull:

`name: Sync from server

on:
schedule:
- cron: '0 4 * * *' # daily at 4am UTC
workflow_dispatch:

jobs:
sync:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v4

  - name: Setup SSH
    run: |
      mkdir -p ~/.ssh
      echo "${{ secrets.SERVER_SSH_KEY }}" > ~/.ssh/id_ed25519
      chmod 600 ~/.ssh/id_ed25519
      ssh-keyscan yourserver.com >> ~/.ssh/known_hosts
      
  - name: Pull from server
    run: |
      git remote add server ssh://you@yourserver.com/path/to/content
      git fetch server
      git merge server/main --no-edit
      
  - name: Push to GitHub
    run: git push`