Automatic decoding of supported literals in REPL

Automatic decoding & display of string, number, and list types in REPL.
General updates to README, style, and comments.

README.md

@@ -1,16 +1,51 @@
 # sapling
 
+## Introduction
+
 sapling is a "micro-language" that I'm working on to investigate [Tree Calculus](https://github.com/barry-jay-personal/typed_tree_calculus/blob/main/typed_program_analysis.pdf) .
 
 It offers a minimal amount of syntax sugar:
 
 - `t` operator behaving by the rules of Tree Calculus
-- Variable definitions
+- Function ("variable") definitions
 - Lambda abstractions
-- List, Integer, and String literals
+- List, Number, and String literals (WIP)
 
 This is an active experimentation project by [someone who has no idea what they're doing](https://eversole.co).
 
+## What does it look like?
+
+```
+false = t
+true = t t
+id = (\\a : a)
+triage = (\\a b c : t (t a b) c) 
+match_bool = (\\ot of : triage of (\\z : ot) t)
+and = match_bool id (\\z : false)
+if = (\\cond then else : t (t else (t t then)) t cond)
+triage = (\\a b c : t (t a b) c)
+test = triage \"leaf\" (\\z : \"stem\") (\\a b : \"fork\")
+
+sapling < test t
+sapling > Fork (...)
+DECODE -: "leaf"
+sapling < test (t t)
+sapling > Fork (...)
+DECODE -: "stem"
+sapling < test (t t t)
+sapling > Fork (...)
+DECODE -: "fork"
+```
+
+## How to use
+
+For now, you can easily build and run this project using Nix:
+
+1. Clone the repository:
+    a. `git clone ssh://git.eversole.co/sapling.git`
+    b. `git clone https://git.eversole/sapling.git`
+1. Run the REPL: `nix run`
+
 ## Acknowledgements 
 
 Tree Calculus was discovered by [Barry Jay](https://github.com/barry-jay-personal/blog).