doc: add README

Author: ProggerX

README.md

@@ -0,0 +1,20 @@
+### ProggerX/chipi-chapa
+# Monadic CHIP-8 emulator written in Haskell
+
+Supports only CHIP-8 instructions for now.
+
+## Installation
+#### Nix 
+If you are lucky nix user, you can use flake in this repo.\
+chipi-chapa is also cached on [our cachix](https://balds.cachix.org)
+
+#### No nix?
+Use cabal idk
+
+## Usage
+- Run chip-8 ROM: `chipi-chapa <path-to-rom>`
+#### Debug
+- Set `CHIPI_CHAPA_DEBUG` env to anything, you will get additional output in stdout.
+
+## Development
+Try `nix develop`.