[tune] Add points_to_evaluate to BasicVariantGenerator (#12916)

Co-authored-by: Richard Liaw <rliaw@berkeley.edu>

doc/source/tune/api_docs/search_space.rst

@@ -263,10 +263,7 @@ Grid Search API
 
 .. autofunction:: ray.tune.grid_search
 
-Internals
----------
+References
+----------
 
-BasicVariantGenerator
-~~~~~~~~~~~~~~~~~~~~~
-
-.. autoclass:: ray.tune.suggest.BasicVariantGenerator
+See also :ref:`tune-basicvariant`.

doc/source/tune/api_docs/suggestion.rst

@@ -22,6 +22,10 @@ Summary
      - Summary
      - Website
      - Code Example
+   * - :ref:`Random search/grid search <tune-basicvariant>`
+     - Random search/grid search
+     -
+     - :doc:`/tune/examples/tune_basic_example`
    * - :ref:`AxSearch <tune-ax>`
      - Bayesian/Bandit Optimization
      - [`Ax <https://ax.dev/>`__]
@@ -123,6 +127,21 @@ identifier.
 
 .. note:: This is currently not implemented for: AxSearch, TuneBOHB, SigOptSearch, and DragonflySearch.
 
+.. _tune-basicvariant:
+
+Random search and grid search (tune.suggest.basic_variant.BasicVariantGenerator)
+--------------------------------------------------------------------------------
+
+The default and most basic way to do hyperparameter search is via random and grid search.
+Ray Tune does this through the :class:`BasicVariantGenerator <ray.tune.suggest.basic_variant.BasicVariantGenerator>`
+class that generates trial variants given a search space definition.
+
+The :class:`BasicVariantGenerator <ray.tune.suggest.basic_variant.BasicVariantGenerator>` is used per
+default if no search algorithm is passed to
+:func:`tune.run() <ray.tune.run>`.
+
+.. autoclass:: ray.tune.suggest.basic_variant.BasicVariantGenerator
+
 .. _tune-ax:
 
 Ax (tune.suggest.ax.AxSearch)