feat: add Random Forest algorithm in machine learning (#1007)

Author: Dcyaprogrammer

DIRECTORY.md

@@ -215,6 +215,7 @@
     * [Naive Bayes](https://github.com/TheAlgorithms/Rust/blob/master/src/machine_learning/naive_bayes.rs)
     * [Perceptron](https://github.com/TheAlgorithms/Rust/blob/master/src/machine_learning/perceptron.rs)
     * [Principal Component Analysis](https://github.com/TheAlgorithms/Rust/blob/master/src/machine_learning/principal_component_analysis.rs)
+    * [Random Forest](https://github.com/TheAlgorithms/Rust/blob/master/src/machine_learning/random_forest.rs)
     * [Support Vector Classifier](https://github.com/TheAlgorithms/Rust/blob/master/src/machine_learning/support_vector_classifier.rs)
     * Loss Function
       * [Average Margin Ranking Loss](https://github.com/TheAlgorithms/Rust/blob/master/src/machine_learning/loss_function/average_margin_ranking_loss.rs)

src/machine_learning/mod.rs

@@ -9,6 +9,7 @@ mod naive_bayes;
 mod optimization;
 mod perceptron;
 mod principal_component_analysis;
+mod random_forest;
 mod support_vector_classifier;
 
 pub use self::cholesky::cholesky;
@@ -25,4 +26,5 @@ pub use self::naive_bayes::naive_bayes;
 pub use self::optimization::{gradient_descent, Adam};
 pub use self::perceptron::{classify, perceptron};
 pub use self::principal_component_analysis::principal_component_analysis;
+pub use self::random_forest::random_forest;
 pub use self::support_vector_classifier::{Kernel, SVCError, SVC};