Add a basic dev container (#42041)

* Add a basic dev container

Adds a basic dev container. This basic development environment has tools like gulp installed

* Update CONTRIBUTING.md

* Move development container seciton to be first tip

* Spaces to tabs and remove comments

Co-authored-by: Daniel Rosenwasser <DanielRosenwasser@users.noreply.github.com>

.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"
+}