old_contents: // Write an efficient algorithm that searches for a value in an m x n matrix. This matrix has the following properties:
  
  // Integers in each row are sorted from left to right.
  // The first integer of each row is greater than the last integer of the previous row.
  // For example,
  
  // Consider the following matrix:
  
  // [
  //   [1,   3,  5,  7],
  //   [10, 11, 16, 20],
  //   [23, 30, 34, 50]
  // ]
  
  // Given target = 3, return true.
  
new_contents: // Write an efficient algorithm that searches for a value in an m x n matrix. This matrix has the following properties:
  
  // Integers in each row are sorted from left to right.
  // The first integer of each row is greater than the last integer of the previous row.
  // For example,
  
  // Consider the following matrix:
  
  // [
  //   [1,   3,  5,  7],
  //   [10, 11, 16, 20],
  //   [23, 30, 34, 50]
  // ]
  
  // Given target = 3, return true.
  
  /**
   * @param {array[][]} matrix
   * @param {number} target
   * @return {boolean}
   */
  
subject: add params