Add a basic dev container

.devcontainer/Dockerfile

@@ -0,0 +1,7 @@
+# See here for image contents: https://github.com/microsoft/vscode-dev-containers/tree/v0.154.0/containers/javascript-node/.devcontainer/base.Dockerfile
+
+# [Choice] Node.js version: 14, 12, 10
+ARG VARIANT="14-buster"
+FROM mcr.microsoft.com/vscode/devcontainers/javascript-node:0-${VARIANT}
+
+RUN sudo -u node npm install -g gulp-cli

.devcontainer/devcontainer.json

@@ -0,0 +1,16 @@
+{
+    "name": "Node.js",
+    "build": {
+        "dockerfile": "Dockerfile",
+        "args": {
+            "VARIANT": "14"
+        }
+    },
+    "settings": {
+        "terminal.integrated.shell.linux": "/bin/bash"
+    },
+    "extensions": [
+        "dbaeumer.vscode-eslint"
+    ],
+    "remoteUser": "node"
+}

CONTRIBUTING.md

@@ -70,6 +70,13 @@ In general, things we find useful when reviewing suggestions are:
 
 ## Tips
 
+### Using a development container
+
+This repository includes a [development container](https://code.visualstudio.com/docs/remote/containers) that you can use to quickly create an isolated development environment with all the tools you need to start working on TypeScript. To get started with a dev container and VS Code, either:
+
+- Clone the TypeScript repository locally and use the `Open Folder in Container` command.
+- Use the `Clone Repository in Container Volume` command to clone the TypeScript repository into a new container.
+
 ### Faster clones
 
 The TypeScript repository is relatively large. To save some time, you might want to clone it without the repo's full history using `git clone --depth=1`.