chore: update README.md

README.md

@@ -1,13 +1,38 @@
 # aoc-2023
 
+[Advent of Code 2023](https://adventofcode.com/2023) solutions written in [Haskell](https://www.haskell.org/).
+
 ## usage
 
-`aoc-2023` contains an entrypoing, which runs all solutions sequentially. In
-addition to this each solutions contains `#eval` statement that shows the
-results in an interactive fashion.
+This project is usable either via `nix` or via `cabal`. I will provide
+commands for both in the following sections.
 
 ### run all solutions
 
+#### nix
+
+```sh
+nix run .#aoc
+```
+
+#### cabal
+
+```sh
+cabal run exe:aoc
+```
+
+### run specific solution
+
+It is possible to run only a specific day. In this example day # `01` is ran.
+
+#### nix
+
+```sh
+nix run .#01
+```
+
+#### cabal
+
 ```sh
-lake exe aoc
+cabal run exe:01
 ```