Example datasets TPC-H and TPC-DS don't show up in sidebar

[rschu1ze]

This PR of mine adds docs for two new example datasets, TPC-H and TPC-DS:
--> ClickHouse/ClickHouse#69877

Google search finds them:

• https://clickhouse.com/docs/en/getting-started/example-datasets/tpch
• https://clickhouse.com/docs/en/getting-started/example-datasets/tpcds

Notice that both pages have no sidebar on the left. In fact, if I start at https://clickhouse.com/docs and navigate to "Example Datasets" (here), I don't find TPC-H and TPC-DS in the sidebar.

Why exactly is this?

[rschu1ze]

@justindeguzman