Feature Request: Add `defaultRowHeight` prop to customize base row height

[iamsameeraliyanage]

Is your feature request related to a problem? Please describe.
I'm always frustrated when the default row height in react-calendar-timeline doesn't match my design requirements. Currently, the timeline rows have a fixed height that can't be easily customized, which makes it difficult to:

• Create more compact timelines when needed
• Accommodate larger content in rows
• Maintain visual consistency with other components in my application

Describe the solution you'd like
I would like a prop (e.g., defaultRowHeight) that allows setting a custom default height for all timeline rows. This prop should:

• Accept a number value (in pixels)
• Be applied as the base height for all rows
• Work in conjunction with the existing dynamic row height functionality
• Maintain all existing functionality like row resizing if enabled

Example usage:

<Timeline
  defaultRowHeight={120}  
  // other props...
/>