Generates a PDF NOTAM briefing.

The app can be used standalone via the navplot.py script, or via GitHub pages to serve PDFs from https://navplot.asselect.uk

In GitHub pages set Build and Deployment source to "GitHub Actions". (The GitHub workflow is defined in .github/workflows/navplot.yaml)

The action is triggered via an external scheduler - see the navplot_scheduler project.

Set the download links in the ASSelect app to: https://navplot.asselect.uk/today_south.pdf, etc.