fix: add missing conundrum_table.hpp from merge

Author: cmayfield

core/include/flip7/conundrum_table.hpp

@@ -0,0 +1,16 @@
+#pragma once
+
+#include <cstddef>
+
+namespace flip7::countdown {
+
+struct ConundrumEntry {
+    const char* solution;
+    const char* scramble;
+    const char* hint;
+};
+
+extern const ConundrumEntry kConundrumTable[];
+extern const std::size_t kConundrumTableSize;
+
+} // namespace flip7::countdown