Updated the devcontainer to support rust-script

.devcontainer/Dockerfile

@@ -0,0 +1,3 @@
+FROM mcr.microsoft.com/devcontainers/rust:1-1-bullseye
+
+RUN cargo install rust-script

.devcontainer/devcontainer.json

@@ -1,6 +1,9 @@
 {
     "name": "Präsentation-Rust Container",
-    "image": "mcr.microsoft.com/devcontainers/rust:1-1-bullseye",
+    
+    "build": {
+        "dockerfile": "Dockerfile"
+    },
     
     "customizations": {
         "vscode": {