improve document system, link actions to db

src/app/core/documents/document.component.ts

src/app/core/documents/document.service.ts

src/app/showcase-site/about-page/about-page.component.html

...pp/showcase-site/actions-page/actions-page.component.html

...pp/showcase-site/actions-page/actions-page.component.scss

src/app/showcase-site/actions-page/actions-page.component.ts

src/app/showcase-site/shared/action.model.ts

src/app/showcase-site/shared/action.service.ts

src/app/showcase-site/shared/index.ts

src/app/showcase-site/showcase-site.module.ts