Remove incorrect example in docs

[lucadonnoh]

Why are these changes needed?

Danksharding doesn't require full nodes to download, store and serve the full bandwidth. See this.

Checks

• [x] I've made sure the lint is passing in this PR.
• [x] I've made sure the tests are passing. Note that there might be a few flaky tests, in that case, please comment that they are not relevant.
• [x] I've checked the new test coverage and the coverage percentage didn't drop.
• Testing Strategy
  • [x] Unit tests
  • [x] Integration tests
  • [ ] This PR is not tested :(