build: create just file for building and running

.gitignore

@@ -22,3 +22,4 @@ cabal.project.local~
 .HTF/
 .ghc.environment.*
 .direnv/
+target/

justfile

@@ -0,0 +1,15 @@
+exec := "musician"
+target := "target"
+
+# list all commands
+default:
+  @just --list
+
+# build musician 
+build:
+  mkdir -p {{target}}
+  ghc -O2 -o {{target}}/{{exec}} *.hs
+
+# run musician 
+run:
+  ./target/{{exec}}