updated randomization docs

com.unity.perception/Documentation~/Randomization/Parameters.md

 # Parameters
 
-## Lookup Parameters
-
-To obtain a parameter from a paramter configuration, use the GetParameter() method:
-```
-// Get a reference to the parameter configuration attached to this GameObject
-var parameterConfiguration = GetComponent<ParameterConfiguration>();
-
-// Lookup the parameter "ObjectWidth" by name
-var parameter = GetComponent<FloatParameter>("ObjectWidth");
-``` 
-
-Parameters are typically managed by `ParameterConfigurations` in the Unity Editor. However, parameters can be instanced independently like a regular class too:
+Parameters are often defined as fields of a randomizer class, but they can also be instanced just like any other C# class:
 ```
 // Create a color parameter
 var colorParameter = new HsvaColorParameter();

com.unity.perception/Documentation~/Randomization/Samplers.md

 Samplers in the perception package are classes that deterministically generate random float values from bounded probability distributions. Although samplers are often used in conjunction with parameters to generate arrays of typed random values, samplers can be instantiated and used from any ordinary script:
 ```
 var sampler = new NormalSampler();
-sampler.seed = 123456789u;
 sampler.mean = 3;
 sampler.stdDev = 2;
 sampler.range = new FloatRange(-10, 10);
 1. Constant Sampler
 2. Uniform Sampler
 3. Normal Sampler 
-4. Placeholder Range Sampler
 
 #### Constant Sampler
 Generates constant valued samples
 #### Normal Sampler
 Generates random samples from a truncated normal distribution bounded by a specified range
 
-#### Placeholder Range Sampler
-Used to define a float range [minimum, maximum] for a particular component of a parameter (example: the hue component of a color parameter). This sampler is useful for configuring sample ranges for non-perception related scripts, particularly when these scripts have a public interface for manipulating a minimum and maximum bounds for their sample range but perform the actual sampling logic internally.
+
+## Custom Samplers
+Take a look at the [UniformSampler](../../Runtime/Randomization/Samplers/SamplerTypes/UniformSampler) and [NormalSampler](../../Runtime/Randomization/Samplers/SamplerTypes/NormalSampler) structs as references for implementing your own [ISampler](../../Runtime/Randomization/Samplers/ISampler). Note that the NativeSamples() method in the ISampler interface requires the usage of the Unity Job System. Take a look [here](https://docs.unity3d.com/Manual/JobSystem.html) to learn more about how to create jobs using the Unity Job System.
-Samplers are designed to be Unity Burst Compiler and Job System compatible to increase simulation performance when generating large numbers of samples. Below is an example of a simple job that uses a NormalSampler directly to create 100 normally distributed samples:
-```
-[BurstCompile]
-public struct SampleJob : IJob
-{
-    NormalSampler sampler;
-    public NativeArray<float> samples;
-    
-    public void Execute()
-    {
-        for (var i = 0; i < samples.Length; i++)
-            samples[i] = sampler.NextSample();
-    }
-}
-```
-Additionally, samplers have a NativeSamples() method that can schedule a ready-made multi-threaded job intended for generating a large array of samples. Below is an example of how to combine two job handles returned by NativeSamples() to generate two arrays of samples simultaneously:
+Samplers have a NativeSamples() method that can schedule a ready-made multi-threaded job intended for generating a large array of samples. Below is an example of how to combine two job handles returned by NativeSamples() to generate two arrays of samples simultaneously:
 ```
 // Create samplers
 var uniformSampler = new UniformSampler
 uniformSamples.Dispose();
 normalSamples.Dispose();
 ```
-
-
-## Custom Samplers
-Take a look at the [UniformSampler](../../Runtime/Randomization/Samplers/SamplerTypes/UniformSampler) and [NormalSampler](../../Runtime/Randomization/Samplers/SamplerTypes/NormalSampler) structs as references for implementing your own [ISampler](../../Runtime/Randomization/Samplers/ISampler). Note that the NativeSamples() method in the ISampler interface requires the usage of the Unity Job System. Take a look [here](https://docs.unity3d.com/Manual/JobSystem.html) to learn more about how to create jobs using the Unity Job System.