fix: inline install script in Dockerfile and update image reference

Fixes #50

- Remove dependency on deleted scripts/ directory by inlining
  wasmtime, cargo-component, and wkg installation in Dockerfile
- Update devcontainer.json to reference the correct published image
  (bytecodealliance/sample-wasi-http-rust-devcontainer)

Author: asw101

.devcontainer/devcontainer.json

@@ -1,5 +1,5 @@
 {
-    "image": "ghcr.io/asw101/rust-wasi-hello-devcontainer:latest",
+    "image": "ghcr.io/bytecodealliance/sample-wasi-http-rust-devcontainer:latest",
     "features": {
         //"ghcr.io/devcontainers/features/rust:1": {},
         "ghcr.io/devcontainers/features/azure-cli:1": {}

.devcontainer/docker/Dockerfile

@@ -3,5 +3,8 @@ FROM mcr.microsoft.com/devcontainers/rust:${TAG}
 
 USER vscode
 
-COPY ./scripts /tmp/scripts/
-RUN bash /tmp/scripts/install.sh
+# Install wasmtime
+RUN curl https://wasmtime.dev/install.sh -sSf | bash
+
+# Install cargo-component and wkg
+RUN cargo install cargo-component wkg