message: chore(release): bump to v1.20.0
diff: {
  "name": "carbon-web-components",
  - "version": "1.19.0",
  + "version": "1.20.0",
  "license": "Apache-2.0",
  "repository": "https://github.com/carbon-design-system/carbon-web-components",
  "bugs": "https://github.com/carbon-design-system/carbon-web-components/issues",
  