Use Dockerfile to allow more custom setup

.devcontainer/Dockerfile

@@ -0,0 +1,13 @@
+FROM ghcr.io/dfinity/icp-dev-env:13
+
+RUN apt -yqq install --no-install-recommends wget
+
+RUN rustup component add clippy
+RUN rustup component add rustfmt
+
+# Install pnpm
+RUN wget -qO- https://get.pnpm.io/install.sh | ENV="$HOME/.bashrc" SHELL="$(which bash)" bash -
+
+# Configures Git to trust all directories as “safe” within the container, bypassing user ownership checks.
+RUN git config --global --add safe.directory '*'
+

.devcontainer/devcontainer.json

@@ -1,6 +1,8 @@
 {
   "name": "ic-alloy-toolkit",
-  "image": "ghcr.io/dfinity/icp-dev-env:13",
+  "build": {
+    "dockerfile": "Dockerfile"
+  },
   "forwardPorts": [
     4943
   ],