Add codespaces support (#3) (#4)

- Adds devcontainer json and related files

.devcontainer/Dockerfile

@@ -0,0 +1,9 @@
+FROM ubuntu:22.04
+
+WORKDIR /home/
+
+COPY . .
+
+RUN bash ./setup.sh
+
+ENV PATH="/root/.cargo/bin:$PATH"

.devcontainer/devcontainer.json

@@ -0,0 +1,15 @@
+{
+	"name": "Clusters",
+	"extensions": [
+		"cschleiden.vscode-github-actions",
+		"rust-lang.rust-analyzer",
+		"serayuzgur.crates",
+		"vadimcn.vscode-lldb"
+	],
+	"dockerFile": "Dockerfile",
+	"settings": {
+		"editor.formatOnSave": true,
+		"terminal.integrated.defaultProfile.linux": "zsh"
+	},
+	"postAttachCommand": "exec zsh"
+}

.devcontainer/setup.sh

@@ -0,0 +1,33 @@
+## update and install some things we should probably have
+apt-get update
+apt-get install -y \
+  curl \
+  git \
+  gnupg2 \
+  jq \
+  sudo \
+  zsh \
+  vim \
+  build-essential \
+  libssl-dev \
+  openssl
+
+## update and install 2nd level of packages
+apt-get install -y pkg-config
+
+## Install rustup and common components
+curl https://sh.rustup.rs -sSf | sh -s -- -y
+export PATH=/root/.cargo/bin:$PATH
+rustup install stable
+rustup component add rustfmt
+rustup component add clippy
+
+cargo install cargo-expand
+cargo install cargo-edit
+
+## setup and install oh-my-zsh
+sh -c "$(curl -fsSL https://raw.githubusercontent.com/robbyrussell/oh-my-zsh/master/tools/install.sh)"
+cp -R /root/.oh-my-zsh /home/$USERNAME
+cp /root/.zshrc /home/$USERNAME
+sed -i -e "s/\/root\/.oh-my-zsh/\/home\/$USERNAME\/.oh-my-zsh/g" /home/$USERNAME/.zshrc
+chown -R $USER_UID:$USER_GID /home/$USERNAME/.oh-my-zsh /home/$USERNAME/.zshrc