feat(content): function signatures + test cases

backend/data/questions/2-keys-keyboard.yaml

@@ -9,6 +9,28 @@ categories:
 patterns:
   - dynamic-programming
 
+function_signature: "def min_steps(n: int) -> int:"
+
+test_cases:
+  visible:
+    - input: { n: 3 }
+      expected: 3
+    - input: { n: 1 }
+      expected: 0
+  hidden:
+    - input: { n: 4 }
+      expected: 4
+    - input: { n: 6 }
+      expected: 5
+    - input: { n: 12 }
+      expected: 7
+    - input: { n: 17 }
+      expected: 17
+    - input: { n: 100 }
+      expected: 14
+    - input: { n: 1000 }
+      expected: 21
+
 description: |
   There is only one character `'A'` on the screen of a notepad. You can perform one of two operations on this notepad for each step: