Add options to readme

README.md

@@ -1,6 +1,30 @@
 exa
 ===
 
-exa is a replacement for `ls` written in Rust. I'm learning Rust as I go.
+exa is a replacement for `ls` written in Rust.
+
+![Build status](https://travis-ci.org/ogham/exa.svg?branch=master)
+
+Screenshot
+----------
 
 ![Screenshot of exa](https://raw.githubusercontent.com/ogham/exa/master/screenshot.png)
+
+Options
+-------
+
+- **-a**, **--all**: show dot files
+- **-b**, **--binary**: use binary (power of two) file sizes
+- **-g**, **--group**: show group as well as user
+- **-h**, **--header**: show a header row
+- **-i**, **--inode**: show inode number column
+- **-l**, **--links**: show number of hard links column
+- **-r**, **--reverse**: reverse sort order
+- **-s**, **--sort=(name, size, ext)**: field to sort by
+- **-S**, **--blocks**: show number of file system blocks
+
+
+Installation
+------------
+
+exa is written in [Rust](http://www.rust-lang.org). You should use the nightly, rather than the 0.10 release, which is rather out of date at this point. Once you have Rust set up, a simple `make` should compile exa.