Doxygen: Amend minor issues (#2593)

Corrects a few issues with regards to Doxygen documentation, for example:

- Incorrect parameter referencing.
- Missing @param tags.
- Typos in @param tags.

and a few minor other issues.

src/audio_core/interpolate.h

@@ -21,6 +21,7 @@ struct State {
 
 /**
  * No interpolation. This is equivalent to a zero-order hold. There is a two-sample predelay.
+ * @param state Interpolation state.
  * @param input Input buffer.
  * @param rate_multiplier Stretch factor. Must be a positive non-zero value.
  *                        rate_multiplier > 1.0 performs decimation and rate_multipler < 1.0
@@ -31,6 +32,7 @@ StereoBuffer16 None(State& state, const StereoBuffer16& input, float rate_multip
 
 /**
  * Linear interpolation. This is equivalent to a first-order hold. There is a two-sample predelay.
+ * @param state Interpolation state.
  * @param input Input buffer.
  * @param rate_multiplier Stretch factor. Must be a positive non-zero value.
  *                        rate_multiplier > 1.0 performs decimation and rate_multipler < 1.0