Add example notebook for visualizing mosquito sample geographic distribution

[priyarai121]

While exploring the malariagen_data API, I noticed that it would be helpful for new users to have a simple example demonstrating how to visualize the geographic distribution of mosquito samples.

Motivation

Understanding the geographic distribution of samples is often one of the first steps when exploring genomic datasets. A clear example notebook could help users quickly understand dataset coverage and perform basic exploratory analysis.

Proposed Contribution

I would like to add a notebook under the examples/ directory that demonstrates how to:

• Load mosquito sample metadata using the malariagen_data API
  -Explore the number of samples collected in different countries
  -Visualize sample distribution using a simple plot

Please let me know if this would be a useful addition or if there are preferred formats or locations for such examples.