message: docs: add `partition` to the operators list
diff: @@ -146,6 +146,7 @@ These are Observable creation operators that also have join functionality -- emi
  - [`concat`](/api/index/function/concat)
  - [`forkJoin`](/api/index/function/forkJoin)
  - [`merge`](/api/index/function/merge)
  +- [`partition`](/api/index/function/partition)
  - [`race`](/api/index/function/race)
  - [`zip`](/api/index/function/zip)
  