Added documentation to HNSWCorpus

Sources/SwiftNLP/1. Data Collection/HNSWCorpus.swift

@@ -27,7 +27,7 @@ import PriorityHeapAlgorithms
 import SimilarityMetric
 import HNSWAlgorithm
 import HNSWEphemeral
-import GameplayKit
+import GameplayKit /// Not avaliable on Linux?
 
 
 class HNSWCorpus<Scalar: BinaryFloatingPoint & Codable>: SNLPCorpus {
@@ -46,7 +46,7 @@ class HNSWCorpus<Scalar: BinaryFloatingPoint & Codable>: SNLPCorpus {
     
     @inlinable
     func addUntokenizedDocument(_ document: String) {
-        // Forced cast to [Scalar] is unnecessary
+        /// Forced cast to [Scalar] is unnecessary
         encodedDocuments.insert((_documentEncoder.encodeSentence(document)))
     }
 }
@@ -78,6 +78,7 @@ public struct DeterministicSampleVectorIndex<Vector: Collection & Codable> where
     public mutating func insert(_ vector: Vector) {
         let convertedVector: [Double] = vector.map{ Double($0) }
         if let metricVector = convertedVector as? CartesianDistanceMetric<Vector>.Vector {
+            /// Returns a Key (unused)
             base.insert(metricVector, using: &graphRNG)
         } else {
             fatalError("Unable to get metric vector")