feat: add launch.json for REPL

The launch configuration first builds then starts the REPL and attaches a debugger to it.
It is important that "console": "integratedTerminal" is set, so that one can still use the REPL.

.vscode/launch.json

@@ -0,0 +1,25 @@
+{
+    // Use IntelliSense to learn about possible attributes.
+    // Hover to view descriptions of existing attributes.
+    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "type": "node",
+            "request": "launch",
+            "name": "Launch Program",
+            "skipFiles": [
+                "node_modules/**"
+            ],
+            "program": "${workspaceFolder}/src/cli/flowr.ts",
+            "preLaunchTask": "npm: build:bundle-flowr",
+            "console": "integratedTerminal",
+        },
+        {
+            "type": "node",
+            "request": "attach",
+            "name": "Attach to Process",
+            "port": 9229
+        }
+    ]
+}