docs: Add install of material-components-web to guide (#1911)
docs: Add install of material-components-web to guide (#1911)

Because `material-components-web` is a peer dependency, it will not install automatically and `@angular-mdc/web` will not work without it (or a few @material/... packages)

NPM will give a warning about this, but it's nicer to just tell people to install the package from the start.
trimox/angular-mdc-web,trimox/angular-mdc-web