Update README with new information

README.md

@@ -1,18 +1,33 @@
 # Rustpad
 
 **Rustpad** is an _efficient_ and _minimal_ open-source collaborative text
-editor based on the operational transformation (OT) algorithm. Rustpad provides
-an online real-time code editor that communicates via WebSocket with a central
-server storing in-memory data structures.
-
-The backend is written in Rust, using
-[Warp](https://github.com/seanmonstar/warp) and the open source
+editor based on the operational transformation (OT) algorithm. Similar to Google
+Docs, Rustpad allows users to collaborate in real time while writing code in
+their browser.
+
+<p align="center">
+<a href="https://rustpad.io/">
+<img src="https://images.placeholders.dev/?width=600&height=300" width="600"><br>
+<strong>Rustpad.io</strong>
+</a>
+</p>
+
+The server is written in Rust using [Warp](https://github.com/seanmonstar/warp)
+and the
 [operational-transform](https://github.com/spebern/operational-transform-rs)
 library, which is a port of
-[ot.js](https://github.com/Operational-Transformation/ot.js). The frontend is
-written in React and interfaces with
-[Monaco](https://github.com/microsoft/monaco-editor), the same text editor that
-powers VS Code.
+[ot.js](https://github.com/Operational-Transformation/ot.js). We compile some of
+this logic to WebAssembly with
+[wasm-bindgen](https://github.com/rustwasm/wasm-bindgen) for use in the browser.
+The frontend is written in TypeScript using [React](https://reactjs.org/) and
+interfaces with [Monaco](https://github.com/microsoft/monaco-editor), the text
+editor that powers VS Code.
+
+Architecturally, client-side code communicates via WebSocket with a central
+server that stores in-memory data structures. This makes the editor very fast,
+allows us to avoid provisioning a database, and makes testing our code much
+easier. The tradeoff is that user documents are transient and lost between
+server restarts.
 
 ## Development setup
 
@@ -30,7 +45,7 @@ application with:
 npm install
 ```
 
-Finally, compile and run the backend web server with:
+Finally, compile and run the backend web server:
 
 ```
 cargo run
@@ -59,8 +74,8 @@ wasm-pack test rustpad-wasm --chrome --headless
 ## Deployment
 
 Rustpad is distributed as a single ~10 MB Docker image, which is built from the
-`Dockerfile` in this repository. We use GitHub Actions to automatically build
-new images on every push to the `main` branch.
+`Dockerfile` in this repository. GitHub Actions automatically builds a new image
+on each push to the `main` branch.
 
-We continuously deploy a single container of this image to the
+We continuously deploy a public instance of this image using
 [DigitalOcean App Platform](https://www.digitalocean.com/products/app-platform/).