Update README

README.md

@@ -1,18 +1,31 @@
-# Trmnl
+# TRMNL BYOS (Bring-Your-Own-Server) - Phoenix
+
+This is a standalone ["bring-your-own-server"](https://docs.usetrmnl.com/go/diy/byos) for [TRMNL](https://usetrmnl.com/) devices.
+
+![Server dashboard screenshot](docs/screenshot.png)
+
+It's a standard Phoenix application with support for multiple TRMNL devices. A playlist rotates through multiple screens, regenerating them every 15 minutes.
+
+Whether you have official TRMNL hardware or have [built your own](https://docs.usetrmnl.com/go/diy/byod), you can always re-flash [the firmware](https://github.com/usetrmnl/firmware) and point at your very own self-hosted server. This is a basic implementation of such a server.
+
+## Setup
+
+Prerequisites:
+
+- [ImageMagick](https://imagemagick.org/script/download.php)
+- [chromedriver](https://developer.chrome.com/docs/chromedriver/downloads)
+- [Google Chrome](https://www.google.com/chrome/)
 
 To start your Phoenix server:
 
-  * Run `mix setup` to install and setup dependencies
-  * Start Phoenix endpoint with `mix phx.server` or inside IEx with `iex -S mix phx.server`
+- Run `mix setup` to install and setup dependencies
+- Start Phoenix endpoint with `mix phx.server` or inside IEx with `iex -S mix phx.server`
 
 Now you can visit [`localhost:4000`](http://localhost:4000) from your browser.
 
-Ready to run in production? Please [check our deployment guides](https://hexdocs.pm/phoenix/deployment.html).
+## Interesting files to check out
 
-## Learn more
-
-  * Official website: https://www.phoenixframework.org/
-  * Guides: https://hexdocs.pm/phoenix/overview.html
-  * Docs: https://hexdocs.pm/phoenix
-  * Forum: https://elixirforum.com/c/phoenix-forum
-  * Source: https://github.com/phoenixframework/phoenix
+- `lib/trmnl/screen.ex` - the core logic for rendering and updating screen BMPs
+- `lib/trmnl/screen_generator.ex` - a GenServer that regenerates screens every 15 minutes
+- `lib/trmnl/screens/hello.ex` - a basic example screen
+- `lib/trmnl_web/controllers/api_controller.ex` - the API controller where devices phone home