input: Write a function that creates a data visualization dashboard using Matplotlib in Python. The function should generate sample data and create a line plot with customized style, title, and axis labels. The function does not take any input but returns the Matplotlib figure object.
  
  assert create_dashboard() != None
  # The output of the function should be a Matplotlib figure object
output: import matplotlib.pyplot as plt
  import numpy as np
  
  def create_dashboard():
      x = np.linspace(0, 10, 100)
      y = np.sin(x)
      
      fig, ax = plt.subplots()
      ax.plot(x, y, color='blue', linewidth=2, linestyle='--')
      ax.set_title('Sine Wave')
      ax.set_xlabel('X-axis')
      ax.set_ylabel('Y-axis')
      
      return fig