update instructions to switch base-href configurations between dev an…

…d prod

README.md

@@ -18,4 +18,8 @@ A Showcase of Applications Developed using ProvenanceWidgets.
 - `npm run build` outputs the build in the `./dist/` folder.
 
 ## Deployment
-- GitHub Actions is setup via the `.github/workflows/build.yaml` file. Built files are pushed to `gh-pages` branch and served via GitHub Pages at [https://provenancewidgets.github.io/showcase](https://provenancewidgets.github.io/showcase).
+- GitHub Actions is setup via the `.github/workflows/build.yaml` file. Built files are pushed to `gh-pages` branch and served via GitHub Pages at [https://provenancewidgets.github.io/showcase](https://provenancewidgets.github.io/showcase).
+
+## Development vs. Building Configurations for base-href
+- Development: Because the app served from `/` while developing locally, index.html must be configured with `<base href="/" />`.
+- Build: Because the app is eventually served from `/showcase` (and not `/`), index.html must be configured with `<base href="/showcase/" />`. In addition, we pass `--base-href /showcase/` in the `ng build` command (already configured to do this as part of `npm run build`, see package.json).