Update README.md before 0.1.0

Author: polybuildr

README.md

@@ -2,11 +2,15 @@
 
 [![Build Status](https://travis-ci.org/polybuildr/balloon-lang.svg?branch=master)](https://travis-ci.org/polybuildr/balloon-lang)
 
-**This is an experimental project.**
+**This is a very experimental project.**
+
+This is an attempt to build a general-purpose interpreted programming language (later with a focus on back-end web programming) that attempts to allow the programmer to choose their own guarantees for things like type safety.
+
+This project is written in Rust. If you're unfamiliar with Rust, you should take a look at the [Rust docs](https://www.rust-lang.org/en-US/documentation.html).
 
 ## Usage
 
-`balloon` is currently not available on crates.io. You will need to built it yourself.
+Balloon is currently not available on crates.io. You will need to build it yourself using Cargo.
 
 ```
 usage: balloon [MODE] FILE
@@ -17,6 +21,8 @@ where MODE is one of:
 --parse    only parse the file, don't run it
 ```
 
+(There is also an (even more) experimental LLVM backend that is not documented here.)
+
 ## Code examples
 
-Examples of valid code can be found by looking at tests in [src/interpreter_test.rs](src/interpreter_test.rs).
+Examples of valid code can be found by looking at tests in the [tests/run-pass](tests/run-pass) directory.