Updated import path for SVR example (#217)

There is no `Rubix\ML\Classifiers\SVR`

Author: DrDub

docs/regressors/svr.md

@@ -33,12 +33,12 @@ public load(string $path) : void
 
 ## Example
 ```php
-use Rubix\ML\Classifiers\SVR;
+use Rubix\ML\Regressors\SVR;
 use Rubix\ML\Kernels\SVM\RBF;
 
 $estimator = new SVR(1.0, 0.03, new RBF(), true, 1e-3, 256.0);
 ```
 
 ## References
 [^1]: C. Chang et al. (2011). LIBSVM: A library for support vector machines.
-[^2]: A. Smola et al. (2003). A Tutorial on Support Vector Regression.
+[^2]: A. Smola et al. (2003). A Tutorial on Support Vector Regression.