Revert "remove node_modules"

This reverts commit 2fb5731f23.

node_modules/spdx-correct/README.md

@@ -0,0 +1,14 @@
+```javascript
+var correct = require('spdx-correct')
+var assert = require('assert')
+
+assert.equal(correct('mit'), 'MIT')
+
+assert.equal(correct('Apache 2'), 'Apache-2.0')
+
+assert(correct('No idea what license') === null)
+
+// disable upgrade option
+assert(correct('GPL-3.0'), 'GPL-3.0-or-later')
+assert(correct('GPL-3.0', { upgrade: false }), 'GPL-3.0')
+```