feat(layout): add `LayoutPolar` #89

Job	Run time
Clippy	2m 3s
Rustfmt	16s
Tests (ubuntu-latest, chrome, plotly_ndarray,plotly_image,static_export_default,debug)	3m 26s
Build Wasm Examples (basic)	54s
Tests (windows-latest, chrome, plotly_ndarray,plotly_image,static_export_chromedriver,debug)	6m 25s
Tests (macos-latest, chrome, plotly_ndarray,plotly_image,static_export_default,debug)	3m 19s
Tests (ubuntu-latest, firefox, plotly_ndarray,plotly_image,static_export_geckodriver,static_expor...	10m 14s
Build Book	3m 30s
semver	48s
Code Coverage	10s
Build Examples (3d_charts)	37s
Build Examples (customization/consistent_static_format_export)	1m 25s
Build Examples (basic_charts)	32s
Build Examples (financial_charts)	32s
Build Examples (custom_controls)	33s
Build Examples (ndarray)	31s
Build Examples (customization/multiple_plots_example)	50s
Build Examples (maps)	42s
Build Examples (kaleido)	1m 18s
Build Examples (images)	45s
Build Examples (subplots)	28s
Build Examples (customization/density_mapbox_example)	52s
Build Examples (shapes)	34s
Build Examples (scientific_charts)	41s
Build Examples (statistical_charts)	34s
Build Wasm Examples (callback-example)	53s
Build Examples (themes)	35s
	43m 27s

Provide feedback