fix hovertext dimension to be matrix/ 2d array type #153

Job	Run time
Code Coverage	19s
Clippy	4m 37s
Build Wasm Examples (basic)	1m 2s
semver	48s
Rustfmt	16s
Tests (macos-latest, chrome, plotly_ndarray,plotly_image,static_export_default,debug)	2m 30s
Build Book	3m 57s
Tests (ubuntu-latest, firefox, plotly_ndarray,plotly_image,static_export_geckodriver,static_expor...	2m 24s
Tests (windows-latest, chrome, plotly_ndarray,plotly_image,static_export_chromedriver,debug)	4m 53s
Tests (ubuntu-latest, chrome, plotly_ndarray,plotly_image,static_export_default,debug)	2m 26s
Build Examples (basic_charts)	36s
Build Examples (images)	57s
Build Examples (custom_controls)	37s
Build Examples (ndarray)	34s
Build Examples (customization/density_mapbox_example)	36s
Build Examples (customization/multiple_plots_example)	37s
Build Examples (maps)	45s
Build Examples (financial_charts)	38s
Build Wasm Examples (callback-example)	59s
Build Examples (subplots)	37s
Build Examples (customization/consistent_static_format_export)	1m 42s
Build Examples (scientific_charts)	33s
Build Examples (shapes)	35s
Build Examples (3d_charts)	37s
Build Examples (statistical_charts)	39s
Build Examples (kaleido)	1m 24s
Build Examples (themes)	36s
	36m 14s

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