Docs: Update ReadMe

README.md

@@ -11,6 +11,10 @@ A project to digitalize high energy physics.
 
 ## Where to learn more 
 
+- Read the associated paper:
+
+  https://arxiv.org/abs/2405.08863
+
 - The documentation for this project is at: 
 
   https://heplean.github.io/HepLean/
@@ -27,7 +31,6 @@ A project to digitalize high energy physics.
 
 - A small example script relating to the three fermion anomaly cancellation condition can be found [here](https://live.lean-lang.org/#code=import%20Mathlib.Tactic.Polyrith%20%0A%0Atheorem%20threeFamily%20(a%20b%20c%20%3A%20ℚ)%20(h%20%3A%20a%20%2B%20b%20%2B%20c%20%3D%200)%20(h3%20%3A%20a%20%5E%203%20%2B%20b%20%5E%203%20%2B%20c%20%5E%203%20%3D%200)%20%3A%20%0A%20%20%20%20a%20%3D%200%20∨%20b%20%3D%200%20∨%20c%20%3D%200%20%20%3A%3D%20by%20%0A%20%20have%20h1%20%3A%20c%20%3D%20-%20(a%20%2B%20b)%20%3A%3D%20by%20%0A%20%20%20%20linear_combination%20h%20%0A%20%20have%20h4%20%3A%20%203%20*%20a%20*%20b%20*%20c%20%3D%200%20%3A%3D%20by%20%0A%20%20%20%20rw%20%5B←%20h3%2C%20h1%5D%0A%20%20%20%20ring%20%0A%20%20simp%20at%20h4%20%0A%20%20exact%20or_assoc.mp%20h4%0A%20%20%0A)
 
-  
 
 ## Contributing 
 
@@ -35,17 +38,19 @@ We follow here roughly the same contribution policies as MathLib4 (which can be
 
 A guide to contributing can be found [here](https://github.com/HEPLean/HepLean/blob/master/CONTRIBUTING.md).
 
-If you want permission to create a pull-request for this repository contact Joseph Tooby-Smith on the lean Zulip, or email. 
+If you want permission to create a pull-request for this repository contact Joseph Tooby-Smith on the lean Zulip, or email.  
 
 ## Installation
 
 ### Installing Lean 4 
 
-See: https://leanprover-community.github.io/get_started.html
+The installation instructions for Lean 4 are given here: https://leanprover-community.github.io/get_started.html. 
 
-### Quick installation 
+### Installing HepLean 
 
-- Clone this repository
-- Open a terminal in the corresponding directory.
-- Run `lake exe cache get`.
-- Run `lake build`. 
+- Clone this repository (or download the repository as a Zip file) 
+- Open a terminal at the top-level in the corresponding directory.
+- Run `lake exe cache get`. The command `lake` should have been installed when you installed Lean.
+- Run `lake build`.
+- Open the directory (not a single file) in Visual Studio Code (or another Lean compatible code editor).
+