Adding PWA submodule

[swalter972]

Trying to add https://hugomods.com/en/docs/pwa/

So far so good till I need to add css , jss en post in the cache

Tried this to cache all css in head-end

{{ range resources.Match "css/**/*.css" }}
  {{ $css := . }}
  <link href="{{ $css.RelPermalink }}" rel="stylesheet" />
  {{/* THIS OPERATION CANNOT BE CACHED BY partialCached. */}}
  {{ partial "pwa/functions/precache" (dict "URL" $css.RelPermalink "Page" .) }}
{{ end }}

And this to cache all js

params:
  pwa:
    caches:
      font:
        max_age: 2592000
        origins: []
        strategy: cache-first
      image:
        max_age: 2592000
        origins: []
        strategy: cache-first
      script:
        max_age: 2592000
        origins: []
        strategy: cache-first
      style:
        max_age: 2592000
        origins: []
        strategy: cache-first
    debug: false
    icon_path: images/pwa/icon.png
    icon_sizes:
    - 48
    - 64
    - 128
    - 144
    - 256
    - 512
    manifest:
      background_color: '#ff4088'
      theme_color: '#ff4088'
    offline_image: images/pwa/offline.png
    precaches:
    - url: /
    - url: /post/

{{ range resources.Match "js/**/*.js" }}
  {{ $js := . }}
  <script src="{{ $js.RelPermalink }}"></script>
  {{/* THIS OPERATION CANNOT BE CACHED BY partialCached. */}}
  {{ partial "pwa/functions/precache" (dict "URL" $js.RelPermalink "Page" .) }}
{{ end }}

and this for config.yaml