Add documentation for LocationProvider interface

klocation/src/commonMain/kotlin/com/addhen/klocation/LocationProvider.kt

@@ -4,8 +4,33 @@ package com.addhen.klocation
 
 import kotlinx.coroutines.flow.Flow
 
+/**
+ * [LocationProvider] defines the contract for platform-specific location provider implementations.
+ *
+ * Implementations of this interface are typically not used directly by application code.
+ * Instead, they are utilized by the [LocationService] to provide location functionality.
+ */
 public interface LocationProvider {
+
+  /**
+   * Requests continuous location updates.
+   *
+   * @return A [Flow] of [LocationState] representing the stream of location updates.
+   * The flow will emit new states as the device's location changes or if there are any errors.
+   */
   public fun requestLocationUpdates(): Flow<LocationState>
+
+  /**
+   * Retrieves the last known location.
+   *
+   * @return A [LocationState] representing the last known location or an error state.
+   */
   public suspend fun getLastKnownLocation(): LocationState
+
+  /**
+   * Stops requesting location updates.
+   *
+   * Call this method to stop receiving location updates when they are no longer needed.
+   */
   public fun stopRequestingLocationUpdates()
 }