README: expand

README.md

@@ -1,4 +1,34 @@
 # Using Trezor as a hardware SSH agent
 
+## Screencast demo usage
 
 [![Demo](https://asciinema.org/a/22959.png)](https://asciinema.org/a/22959)
+
+## Installation
+
+First, make sure that the latest `trezorlib` Python package
+is installed correctly:
+
+	$ pip install Cython trezor
+
+Then, install `trezor-agent`:
+
+	$ pip install trezor_agent
+
+## Public key generation
+
+Run:
+
+	$ trezor-agent ssh.hostname.com -v > hostname.pub
+
+Append `hostname.pub` contents to `~/.ssh/authorized_keys`
+configuration file at `ssh.hostname.com`, so the remote server
+would allow you to login using the corresponding private key signature.
+
+## Usage
+
+Run:
+
+	$ trezor-agent ssh.hostname.com -v -c
+
+Make sure to confirm SSH signature on the Trezor device when requested.