Ebenezer's VizHub Assignment
This bar chart displays the median PTEN gene expression across various human tissues, with each bar color-coded by tissue type based on a tissue_info.json file. The visualization aggregates individual sample measurements from a gene expression JSON file, calculating the median expression per tissue using `d3.median`. Users can sort the bars alphabetically or by descending median value through `sortEntries`. The SVG chart is rendered using `d3.scaleBand` and `d3.scaleLinear`, with axes generated via `d3.axisBottom` and `d3.axisLeft`.