Fix duplicate keys issue with ol and ul

[unindented]

Fixes #250

---

This could have been caught with ESLint. We could configure with an .eslintrc.json like:

{
  "parserOptions": {
    "ecmaVersion": "latest",
    "sourceType": "module",
    "ecmaFeatures": {
      "jsx": true
    }
  },
  "env": {
    "node": true,
    "jest": true
  },
  "extends": "eslint:recommended"
}

And it would have complained like this:

tailwindcss-typography/src/styles.js
  108:9  error  Duplicate key 'ol'  no-dupe-keys
  114:9  error  Duplicate key 'ul'  no-dupe-keys
  290:9  error  Duplicate key 'ol'  no-dupe-keys
  296:9  error  Duplicate key 'ul'  no-dupe-keys
  472:9  error  Duplicate key 'ol'  no-dupe-keys
  478:9  error  Duplicate key 'ul'  no-dupe-keys
  654:9  error  Duplicate key 'ol'  no-dupe-keys
  660:9  error  Duplicate key 'ul'  no-dupe-keys
  836:9  error  Duplicate key 'ol'  no-dupe-keys
  842:9  error  Duplicate key 'ul'  no-dupe-keys

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[unindented]

I think the issue got introduced in #216. @adamwathan could you take a quick look?

[adamwathan]

Not today but hoping to catch up on issues and PRs over the next couple of weeks. Thanks!

[RobinMalfait]

Hey! Thank you for your PR!
Much appreciated! 🙏

Yep this bug got introduced incorrectly, the good part is that there is not much of a visual difference because of margin collapsing