website: require Node v12

Start using Node.js v12.19.0, the most recent active LTS that is
supported by Vercel:
https://vercel.com/docs/runtimes#official-runtimes/node-js/node-js-version
.

The docs now require String.prototype.matchAll, that's part of ES2020
support, and is not available on Node.js 10.x.

website/Dockerfile

@@ -1,4 +1,4 @@
-FROM docker.mirror.hashicorp.services/node:10.16.3-alpine
+FROM docker.mirror.hashicorp.services/node:12.19.0-alpine
 RUN apk add --update --no-cache git make g++ automake autoconf libtool nasm libpng-dev
 
 COPY ./package.json /website/package.json

website/Makefile

@@ -38,8 +38,6 @@ build-image:
 # Use this if you have run `build-image` to use the locally built image
 # rather than our CI-generated image to test dependency changes.
 website-local:
-	@echo "==> Downloading latest Docker image..."
-	@docker pull hashicorp/nomad-website
 	@echo "==> Starting website in Docker..."
 	@docker run \
 		--interactive \

website/README.md

@@ -48,7 +48,7 @@ The docker image is pre-built with all the website dependencies installed, which
 
 ### With Node
 
-If your local development environment has a supported version (v10.0.0+) of [node installed](https://nodejs.org/en/) you can run:
+If your local development environment has a supported version (v12.0.0+) of [node installed](https://nodejs.org/en/) you can run:
 
 - `npm install`
 - `npm start`
@@ -146,6 +146,7 @@ $ curl ...
 </Tab>
 </Tabs>
 
+
 Contined normal markdown content
 ````