Update Node.js requirement documentation

Update Node.js version specified in README.md to be explicit about which
versions below 12 is supported, and use version 12 by default.

Dockerfile

@@ -1,6 +1,6 @@
 # Warning: This is currently broken as a result of
 # changes done in the 2.0 refactoring.
-FROM node:10
+FROM node:12
 RUN apt-get update && apt install git curl tar -y
 RUN mkdir factorioClusterio
 

README.md

@@ -101,11 +101,12 @@ Clusterio can also do a few other neat things, such as giving you access to epoc
 **Warning**: These instructions are for the unstable master version and is not
 recommended for use, see [the 1.2.x branch][1.2.x] for how to install the stable version.
 
-NodeJS does not support EOL ubuntu releases. Make sure you are on the most recent LTS release or newer.
+Clusterio runs on Node.js v12 and up, v11.13.0+ and v10.16.0+.  Node.js itself is not
+supported on EOL Ubuntu releases so make sure you're on a recent release of Ubuntu.
 
 Master and all slaves:
 
-    wget -qO - https://deb.nodesource.com/setup_10.x | sudo -E bash -
+    wget -qO - https://deb.nodesource.com/setup_12.x | sudo -E bash -
     sudo apt install -y nodejs python-dev git build-essential
     git clone -b master https://github.com/clusterio/factorioClusterio.git
     cd factorioClusterio
@@ -159,7 +160,8 @@ Game Client = The people connecting to the server
 
 **Requirements**
 
-download and install nodeJS 10 from http://nodejs.org
+download and install nodeJS 12 from http://nodejs.org.  Clusterio runs on Node.js v12 and
+up, v11.13.0+ and v10.16.0+.
 
 download and install git from https://git-scm.com/
 

package.json

@@ -26,7 +26,7 @@
   "author": "Danielv123",
   "license": "MIT",
   "engines": {
-    "node": ">=10"
+    "node": ">=10.16 <11 || >= 11.13"
   },
   "dependencies": {
     "as-table": "^1.0.31",