Update README.md

Instalation instructions

README.md

@@ -1,8 +1,27 @@
 [![GitHub (pre-)release](https://img.shields.io/github/release/vasilsaroka/TBpack/all.svg)](https://github.com/vasilsaroka/TBpack/releases)
 [![Github All Releases](https://img.shields.io/github/downloads/vasilsaroka/TBpack/total.svg)](https://github.com/vasilsaroka/TBpack/releases)
-[![License: CC BY-NC 4.0](https://img.shields.io/badge/License-CC%20BY--NC%204.0-lightgrey.svg)](https://creativecommons.org/licenses/by-nc/4.0/)
+[![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg)](https://opensource.org/licenses/MIT)
 
 
 
 # TBpack
-Tight-binding calculations for carbon based nanostructures in Mathematica
+Tight-binding calculations in Mathematica
+
+## Installation
+
+ - [Download the latest release](https://github.com/vasilsaroka/TBpack/releases), distributed as a `.paclet` file, and install it using the `PacletInstall` function in Mathematica:
+
+        Needs["PacletManager`"]
+        PacletInstall["path2paclet"]
+        
+   Insert `path2paclet` via Mathematica's Insert → File Path... menu command.
+
+ - Evaluate ``<<TBpack` `` to load the application into the Mathematica session.
+ - Test TBpack using `AtomicStructure[Nanotube[10, 10]]`.
+ - Test MaTeX using `MaTeX["x^2"]`.
+
+   Packages [MaTeX](https://github.com/szhorvat/MaTeX/releases) by Szabolcs Horvát and [CustomTicks](https://library.wolfram.com/infocenter/Demos/5599/) by Mark A. Caprio  are integral parts of `TBpack`.
+
+   Compilation to C code is used in TBpack to speed up optical absorption spectra calculations. See [how to make Mathematica working with C compiler on Windows](https://sites.google.com/site/sarokavasil/wolfram-mathematica). If compiler is not available Mathematica will run uncompiled function.
+
+ - Open the documentation center and search for "Hamiltonian" to get started.