tools: lint for additional strings in docs

Check for uses of `Github` (rather than `GitHub`) and `Node.JS` (rather
than `Node.js`) in markdown files.

PR-URL: https://github.com/nodejs/node/pull/17492
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Anatoli Papirovski <apapirovski@mac.com>
Reviewed-By: Jon Moss <me@jonathanmoss.me>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Daniel Bevenius <daniel.bevenius@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>

tools/remark-preset-lint-node/index.js

@@ -42,8 +42,10 @@ module.exports.plugins = [
   [
     require('remark-lint-prohibited-strings'),
     [
-      { no: 'v8', yes: 'V8' },
-      { no: 'Javascript', yes: 'JavaScript' }
+      { no: 'Github', yes: 'GitHub' },
+      { no: 'Javascript', yes: 'JavaScript' },
+      { no: 'Node.JS', yes: 'Node.js' },
+      { no: 'v8', yes: 'V8' }
     ]
   ],
   [require('remark-lint-strong-marker'), '*'],