Added a 'clean' script to cleanup build directories

clean.sh

@@ -0,0 +1,18 @@
+echo "Cleaning build directories"
+
+CSHARP_DIR="csharp_mod"
+RUST_DIR="rust_compiler"
+
+cd "$CSHARP_DIR"
+dotnet clean
+
+cd ..
+
+cd "$RUST_DIR"
+cargo clean
+
+cd ..
+
+if [[ -d "release" ]]; then
+  rm -rd release
+fi