Remove Default for SamplingStrategy and add docs

The default value was not a good choice whatsoever,
 and forcing the user to choose makes them at least put thought into it,
  especially with better documentation on it.

src/whisper_params.rs

@@ -5,24 +5,29 @@ use std::marker::PhantomData;
 use std::sync::Arc;
 use whisper_rs_sys::whisper_token;
 
+/// The sampling strategy to use to pick tokens from a list of likely possibilities.
 #[derive(Debug, Clone)]
 pub enum SamplingStrategy {
+    /// Greedy sampling: picks the token with the highest probability after having seen `best_of` tokens.
     Greedy {
+        /// Defaults to 5 in `whisper.cpp`. Will be clamped to at least 1.
         best_of: c_int,
     },
+    /// Beam search. Much harder to explain in a blurb.
+    /// Tends to be more accurate in exchange for more CPU time.
     BeamSearch {
+        /// The maximum width of the beam.
+        /// Higher values are better (to a point) at the cost of exponential CPU time.
+        ///
+        /// Defaults to 5 in `whisper.cpp`. Will be clamped to at least 1.
         beam_size: c_int,
-        // not implemented in whisper.cpp as of this writing (v1.2.0)
+        /// Not implemented in `whisper.cpp` as of this writing (02-08-2025, `whisper.cpp` v1.7.6).
+        ///
+        /// Defaults to -1.0.
         patience: c_float,
     },
 }
 
-impl Default for SamplingStrategy {
-    fn default() -> Self {
-        Self::Greedy { best_of: 1 }
-    }
-}
-
 #[derive(Debug, Clone)]
 pub struct SegmentCallbackData {
     pub segment: i32,
@@ -63,9 +68,13 @@ impl<'a, 'b> FullParams<'a, 'b> {
                 fp.greedy.best_of = best_of;
             }
             SamplingStrategy::BeamSearch {
-                beam_size,
+                mut beam_size,
                 patience,
             } => {
+                if beam_size < 1 {
+                    beam_size = 1;
+                }
+
                 fp.beam_search.beam_size = beam_size;
                 fp.beam_search.patience = patience;
             }