docs: add pwa-install-prompt description

Signed-off-by: S. Amir Mohammad Najafi <[email protected]>

README.md

@@ -7,6 +7,7 @@ Here is a brief overview of the included libraries:
 1. [`web-app-toolkit`](./packages/web-app-toolkit): Bundle all browser based nexim's web app toolkit packages into single package.
 2. [`eleventy-config`](./packages/eleventy-config): An optimized, production-ready configuration for the [Eleventy](https://www.11ty.dev/) static site generator tailored for the [Nexim APP Template](https://github.com/the-nexim/nexim-app) structure.
 3. [`service-worker-notify`](./packages/service-worker-notify/) Handles service worker notifications and displays snackbar messages with our without Close Button.
+4. [`pwa-install-prompt`](./packages/pwa-install-prompt/) PWA install prompt handler.
 
 For more detailed information and guidelines on how to use each package, please refer to each package's README.