- Linting: Lint hidden ncurc.js file

- Docs: Add 6.0.0.md migration file
- Docs: Update Contributing, Testing (renamed to Development), Linting and ReleaseInstructions
- Docs: Info on submodules
- npm: Add scripts for updating submodules
- npm: Add `license-badges`, `build-docs`, and `copy` scripts to `prepublishOnly` script
- npm: Bump to 6.0.0

package-lock.json

@@ -1,6 +1,6 @@
 {
   "name": "svgedit",
-  "version": "5.1.0",
+  "version": "6.0.0",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {