Fix client side example readme

docs/examples/client-side-use-on-web-browser/README.md

@@ -1,17 +1,41 @@
 # Client-side use on Web Browser
 
+## Server
+
+The [`server.js`](server.js) Node.js program serves the files in the current directory and also serves the `perfetto` module from [`../../../index.mjs`](../../../index.mjs).
+
+It also exposes the following endpoints:
+
+- `/api/perftrace` (`POST`) - Reads the performance trace from the HTTP request body, writes it to a file and closes the server
+- `/api/data[0-7]` (`GET`) - Serves `{"text": "<text-to-display-by-the-client>"}` after an artificial delay
+- `/api/submit` (`GET`) - Serves `{"data": "<submission-button-text>"}` after an artificial delay
+
+## Client
+
+The `perftrace.mjs` module is `import`ed in (only works here because the server is designed to serve the file with this name):
+
+https:/RaisinTen/perftrace/blob/fbb0d21f13329eee9912373482e7821f61441621/docs/examples/client-side-use-on-web-browser/index.mjs#L1
+
 A new `TraceEvents` object is created in:
 
-TODO
+https:/RaisinTen/perftrace/blob/fbb0d21f13329eee9912373482e7821f61441621/docs/examples/client-side-use-on-web-browser/index.mjs#L4
+
+The client displays a list of loader animations while fetching the data from the `/api/data[0-7]` endpoint in parallel and display those in:
+
+https:/RaisinTen/perftrace/blob/fbb0d21f13329eee9912373482e7821f61441621/docs/examples/client-side-use-on-web-browser/index.mjs#L10-L24
 
-Before the process exits, the `TraceEvents` object is destroyed and the trace events are stringified and printed to `events.json` in:
+The loads are measured using the Performance Timeline APIs:
 
-TODO
+```js
+performance.mark("before");
+// code to measure
+performance.measure("after", "before");
+```
 
-The `require()` calls can be tracked by passing `true` to `trackRequires()` like it is being done in:
+Once the data is fully loaded, a button is displayed, clicking which, sends the performance trace to the `/api/perftrace` endpoint which causes the server to write the performance trace to a file and shut down:
 
-TODO
+https:/RaisinTen/perftrace/blob/fbb0d21f13329eee9912373482e7821f61441621/docs/examples/client-side-use-on-web-browser/index.mjs#L47-L61
 
-After running `node .` and opening <http://localhost:3000> in your browser, the generated `events.json` file can be opened on <https://ui.perfetto.dev> for visualization:
+After running `node server.js`, opening <http://localhost:8080> in your browser and clicking the `Submit trace` button, the generated `events.json` file can be opened on <https://ui.perfetto.dev> for visualization:
 
 ![](./perfetto.png)