Use mem.eql for dictionary test

src/dict.zig

@@ -62,18 +62,8 @@ fn loadDict() []const Wordle.Word {
 // TODO: binary search? need to assert that words are sorted
 pub fn isInDictionary(word: Wordle.Word) bool {
     // exhaustively search through dictionary
-    for (getDictionary()) |entry| {
-        // compare each letter at a time
-        var match = true;
-        for (entry, word) |entryLetter, wordLetter| {
-            if (entryLetter != wordLetter) {
-                match = false;
-                break;
-            }
-        }
-
-        // if every letter matches, return a complete match
-        if (match) {
+    for (getDictionary()) |*entry| {
+        if (std.mem.eql(u8, entry, &word)) {
             return true;
         }
     }
@@ -93,7 +83,7 @@ fn expectNotDictionary(word: Wordle.WordLiteral) !void {
 }
 
 test "in dictionary" {
-    try expectDictionary("abash");
+    try expectDictionary("aback");
 }
 
 test "not in dictionary" {