Amend Levenshtrie creation to use Add since it's faster

Author: andrewjsaid

src/Levenshtypo.Benchmarks/LevenshtrieConstructionTests.cs

@@ -16,8 +16,30 @@ public class LevenshtrieConstructionTests
     public object Numbers_Dictionary() => new Dictionary<string, string>(_1000Entries.Select(w => new KeyValuePair<string, string>(w, w)));
 
     [Benchmark]
-    public object English_Levenshtypo() => Levenshtrie<string>.Create(_englishWords.Select(w => new KeyValuePair<string, string>(w, w)));
+    public object English_Levenshtypo() => Levenshtrie.Create(_englishWords.Select(w => new KeyValuePair<string, string>(w, w)));
 
     [Benchmark]
-    public object Numbers_Levenshtypo() => Levenshtrie<string>.Create(_1000Entries.Select(w => new KeyValuePair<string, string>(w, w)));
+    public object Numbers_Levenshtypo() => Levenshtrie.Create(_1000Entries.Select(w => new KeyValuePair<string, string>(w, w)));
+
+    [Benchmark]
+    public object English_Levenshtypo_Add()
+    {
+        var trie = Levenshtrie.CreateEmpty<string>();
+        foreach (var item in _englishWords)
+        {
+            trie.Add(item, item);
+        }
+        return trie;
+    }
+
+    [Benchmark]
+    public object Numbers_Levenshtypo_Add()
+    {
+        var trie = Levenshtrie.CreateEmpty<string>();
+        foreach (var item in _1000Entries)
+        {
+            trie.Add(item, item);
+        }
+        return trie;
+    }
 }