refactor: Enhance docs in UnitConversions

src/main/java/com/thealgorithms/conversions/UnitConversions.java

@@ -5,10 +5,47 @@
 import java.util.Map;
 import org.apache.commons.lang3.tuple.Pair;
 
+/**
+ * A utility class to perform unit conversions between different measurement systems.
+ *
+ * <p>Currently, the class supports temperature conversions between several scales:
+ * Celsius, Fahrenheit, Kelvin, Réaumur, Delisle, and Rankine.
+ *
+ * <h2>Example Usage</h2>
+ * <pre>
+ *   double result = UnitConversions.TEMPERATURE.convert("Celsius", "Fahrenheit", 100.0);
+ *   // Output: 212.0 (Celsius to Fahrenheit conversion of 100°C)
+ * </pre>
+ *
+ * <p>This class makes use of an {@link UnitsConverter} that handles the conversion logic
+ * based on predefined affine transformations. These transformations include scaling factors
+ * and offsets for temperature conversions.
+ *
+ * <h2>Temperature Scales Supported</h2>
+ * <ul>
+ *   <li>Celsius</li>
+ *   <li>Fahrenheit</li>
+ *   <li>Kelvin</li>
+ *   <li>Réaumur</li>
+ *   <li>Delisle</li>
+ *   <li>Rankine</li>
+ * </ul>
+ */
 public final class UnitConversions {
     private UnitConversions() {
     }
 
+    /**
+     * A preconfigured instance of {@link UnitsConverter} for temperature conversions.
+     * The converter handles conversions between the following temperature units:
+     * <ul>
+     *   <li>Kelvin to Celsius</li>
+     *   <li>Celsius to Fahrenheit</li>
+     *   <li>Réaumur to Celsius</li>
+     *   <li>Delisle to Celsius</li>
+     *   <li>Rankine to Kelvin</li>
+     * </ul>
+     */
     public static final UnitsConverter TEMPERATURE = new UnitsConverter(Map.ofEntries(entry(Pair.of("Kelvin", "Celsius"), new AffineConverter(1.0, -273.15)), entry(Pair.of("Celsius", "Fahrenheit"), new AffineConverter(9.0 / 5.0, 32.0)),
         entry(Pair.of("Réaumur", "Celsius"), new AffineConverter(5.0 / 4.0, 0.0)), entry(Pair.of("Delisle", "Celsius"), new AffineConverter(-2.0 / 3.0, 100.0)), entry(Pair.of("Rankine", "Kelvin"), new AffineConverter(5.0 / 9.0, 0.0))));
 }

src/test/java/com/thealgorithms/conversions/UnitConversionsTest.java

@@ -13,8 +13,8 @@
 
 public class UnitConversionsTest {
     private static void addData(Stream.Builder<Arguments> builder, Map<String, Double> values) {
-        for (final var first : values.entrySet()) {
-            for (final var second : values.entrySet()) {
+        for (var first : values.entrySet()) {
+            for (var second : values.entrySet()) {
                 if (!first.getKey().equals(second.getKey())) {
                     builder.add(Arguments.of(first.getKey(), second.getKey(), first.getValue(), second.getValue()));
                 }