Add production files generation CI job

[apcountryman]

Add production files generation CI job. The proposed design was outlined in #25.

• Add KiBot as a repository submodule:

  git submodule add ../KiBot utilities/KiBot

• [ ] Add production files generation CI script (ci/generate-production-files):
  • [ ] Supported options:
    • [ ] --help: See other project scripts
    • [ ] --version: See other project scripts
  • [ ] function error(): See other project scripts
  • [ ] function abort(): See other project scripts
  • [ ] function display_help_text(): See other project scripts
  • [ ] function display_version(): See other project scripts
  • [ ] function main(): See other project scripts
  • [ ] function generate_production_files():

    
    local layouts; mapfile -t layouts < <( git -C "$repository" ls-files '*.kicad_pcb' | xargs -r -d '\n' -I '{}' find "$repository/{}" ); readonly layouts

for layout in "${layouts[@]}"; do if ! "$repository/utilities/KiBot/src/kibot" -b "$layout" -c "$repository/kibot.yml" -d "$repository/production-files"; then abort fi done

- [ ] Add KiBot configuration file (`kibot.yml`):
```yaml
kibot:
    version: 1

preflight:
    check_zone_fills: false
    run_drc: false
    run_erc: false
    update_xml: false

global:
    output: '%f-%i.%x'

outputs:
    - name: 'Gerbers'
      type: 'gerber'
      dir: 'gerber'
      options:
          create_gerber_job_file: true
          exclude_edge_layer: true
          exclude_pads_from_silkscreen: true
          force_plot_invisible_refs_vals: false
          gerber_precision: 4.6
          line_width: 0.1
          plot_footprint_refs: true
          plot_footprint_values: false
          plot_sheet_reference: false
          subtract_mask_from_silk: false
          tent_vias: false
          use_aux_axis_as_origin: false
          use_gerber_net_attributes: true
          use_gerber_x2_attributes: false
          use_protel_extensions: false
      layers:
          - layer: 'F.Cu'
          - layer: 'In1.Cu'
          - layer: 'In2.Cu'
          - layer: 'B.Cu'
          - layer: 'F.Paste'
          - layer: 'B.Paste'
          - layer: 'F.SilkS'
          - layer: 'B.SilkS'
          - layer: 'F.Mask'
          - layer: 'B.Mask'
          - layer: 'Edge.Cuts'

    - name: 'Drill'
      type: 'excellon'
      dir: 'gerber'
      options:
          map:
              type: 'gerber'
          metric_units: true
          minimal_header: false
          mirror_y_axis: false
          pth_and_npth_single_file: true
          use_aux_axis_as_origin: false

    - name: 'Pick and Place'
      type: 'position'
      dir: 'pick-and-place'
      options:
          format: 'ASCII'
          only_smd: true
          separate_files_for_front_and_back: true
          units: 'millimeters'

• [ ] Add production files generation (and archiving) CI job to .github/workflows/ci/yml:

  generate-production-files:
  name: Generate production files
  runs-on: ubuntu-20.04
  steps:
      - uses: actions/checkout@v2
          with:
              submodules: recursive
      - name: Generate production files
          shell: bash
          run: ./ci/generate-production-files
      - name: Archive generated production files
          uses: actions/upload-artifact@v2
          with:
              name: production-files
              path: production-files
              retention-days: 7