docs: improve tunables description

Signed-off-by: Jérôme Benoit <jerome.benoit@piment-noir.org>

diff --git a/README.md b/README.md
index fb09dfaad48ae97820dea6992d348f177aa16ae2..0c867eafeba18da8a6a4825dbf9d5a5fabe518d0 100644 (file)
--- a/README.md
+++ b/README.md
@@ -102,7 +102,7 @@ docker compose up -d --build
 | freqai.predictions_extrema.extrema_fraction          | 1.0               | float (0,1]                                                                                                                      | Fraction of extrema used for thresholds. `1.0` uses all, lower values keep only most significant. Applies to `rank` and `values`; ignored for `partition`.                                                                                                                                                   |
 | _Optuna / HPO_                                       |                   |                                                                                                                                  |                                                                                                                                                                                                                                                                                                              |
 | freqai.optuna_hyperopt.enabled                       | true              | bool                                                                                                                             | Enables HPO.                                                                                                                                                                                                                                                                                                 |
-| freqai.optuna_hyperopt.sampler                       | `tpe`             | enum {`tpe`,`auto`}                                                                                                              | HPO sampler algorithm. `tpe` uses TPESampler with multivariate and group, `auto` uses AutoSampler.                                                                                                                                                                                                           |
+| freqai.optuna_hyperopt.sampler                       | `tpe`             | enum {`tpe`,`auto`}                                                                                                              | HPO sampler algorithm. `tpe` uses TPESampler with multivariate and group, `auto` uses [AutoSampler](https://hub.optuna.org/samplers/auto_sampler).                                                                                                                                                           |
 | freqai.optuna_hyperopt.storage                       | `file`            | enum {`file`,`sqlite`}                                                                                                           | HPO storage backend.                                                                                                                                                                                                                                                                                         |
 | freqai.optuna_hyperopt.continuous                    | true              | bool                                                                                                                             | Continuous HPO.                                                                                                                                                                                                                                                                                              |
 | freqai.optuna_hyperopt.warm_start                    | true              | bool                                                                                                                             | Warm start HPO with previous best value(s).                                                                                                                                                                                                                                                                  |