Update "Requirements" and "Getting started" README sections (#205)

I hope this makes `README.md` a bit more friendly for our early adopters, but any feedback is welcome as usual 🙂

README.md

@@ -21,16 +21,6 @@ forget to check [the "Contributing" section](https://github.com/swiftwasm/Tokama
 If you'd like to participate in the growing [SwiftWasm](https://swiftwasm.org) community, you're also very
 welcome to join the `#webassembly` channel in [the SwiftPM Slack](https://swift-package-manager.herokuapp.com/).
 
-## Getting started
-
-Tokamak relies on [`carton`](https://carton.dev) as a primary build tool. Please follow
-[installation instructions](https://github.com/swiftwasm/carton#requirements) for `carton` first.
-
-After `carton` is successfully installed, type `carton dev --product TokamakDemo` in the
-root directory of the cloned Tokamak repository. This will build the demo project and its
-dependencies and launch a development HTTP server. You can then open
-[http://127.0.0.1:8080/](http://127.0.0.1:8080/) in your browser to interact with the demo.
-
 ### Example code
 
 Tokamak API attempts to resemble SwiftUI API as much as possible. The main difference is
@@ -115,6 +105,67 @@ This way both [Semantic UI](https://semantic-ui.com/) styles and [moment.js](htt
 localized date formatting (or any arbitrary style/script/font added that way) are available in your
 app.
 
+## Requirements for app developers
+
+- macOS 10.15 and Xcode 11.4 or later for macOS.
+- [Swift 5.2 or later](https://swift.org/download/) for Linux.
+
+## Requirements for app users
+
+Any browser that [supports WebAssembly](https://caniuse.com/#feat=wasm) should work, which currently includes:
+
+- Edge 16+
+- Firefox 53+
+- Chrome 57+
+- (Mobile) Safari 11+
+
+Not all of these were tested though, compatibility reports are very welcome!
+
+## Getting started
+
+Tokamak relies on [`carton`](https://carton.dev) as a primary build tool. As a part of these steps
+you'll install `carton` via [Homebrew](https://brew.sh/) on macOS (unfortunately you'll have to build
+it manually on Linux). Assuming you already have Homebrew installed, you can create a new Tokamak 
+app by following these steps:
+
+1. Install `carton`:
+
+```
+brew install swiftwasm/tap/carton
+```
+
+If you had `carton` installed before this, make sure you have version 0.4.1 or greater:
+
+```
+carton --version
+```
+
+2. Create a directory for your project and make it current:
+
+```
+mkdir TokamakApp && cd TokamakApp
+```
+
+3. Initialize the project from a template with `carton`:
+
+```
+carton init --template tokamak
+```
+
+4. Build the project and start the development server, `carton dev` can be kept running
+during development:
+
+```
+carton dev
+```
+
+5. Open [http://127.0.0.1:8080/](http://127.0.0.1:8080/) in your browser to see the app
+running. You can edit the app source code in your favorite editor and save it, `carton` 
+will immediately rebuild the app and reload all browser tabs that have the app open.
+
+You can also clone this repository and run `carton dev` in its root directory. This
+will build the demo app that shows almost all of the currently implemented APIs.
+
 ## Contributing
 
 ### Modular structure