Fixing pkgdown navbar

[VisruthSK]

Summary

Add Articles back to navbar

Copyright and Licensing

By submitting this pull request, the copyright holder is agreeing to
license the submitted work under the following licenses:

• Code: BSD 3-clause (https://opensource.org/licenses/BSD-3-Clause)
• Documentation: CC-BY 4.0 (https://creativecommons.org/licenses/by/4.0/)

[github-actions]

This is how benchmark results would change (along with a 95% confidence interval in relative change) if 83f10b1 is merged into master:

• ✔️as_draws_array: 127ms -> 126ms [-2.74%, +1.55%]
• ✔️as_draws_df: 74.4ms -> 75.6ms [-1.32%, +4.43%]
• ✔️as_draws_list: 130ms -> 129ms [-3.09%, +1.3%]
• ✔️as_draws_matrix: 17.3ms -> 17.2ms [-1.64%, +0.54%]
• ✔️as_draws_rvars: 101ms -> 101ms [-3.97%, +3.32%]
• ✔️summarise_draws_100_variables: 468ms -> 466ms [-1.54%, +0.87%]
• ✔️summarise_draws_10_variables: 53.1ms -> 53.3ms [-0.63%, +1.3%]
  Further explanation regarding interpretation and methodology can be found in the documentation.