Avoid argument explosion in plotting functions

• Additional function parameters / changed functionality / changed defaults?
• New analysis tool: A simple analysis tool you have been using and are missing in sc.tools?
• New plotting function: A kind of plot you would like to seein sc.pl?
• External tools: Do you know an existing package that should go into sc.external.*?
• Other?

To reduce the number of arguments that are passed to plotting functions and to agrupate them by type I was considering the following example syntax:

sc.pl.umap(adata, color='clusters').scatter_outline(width=0.1)
                                   .legend(loc='on data',  outline=1)
                                   .add_edges(color='black', width=0.1)

or

sc.pl.dotplot(adata, ['gene1', 'gene2'], groupby='clusters')
                     .add_dendrogram(width=0.4,color='grey')
                     .swap_axes()
                     .dot_size_legend(title='fraction', location='left')

Any comments?
(I am not sure how to implement something like this)

Start by reviewing the plotting entry points named in the issue, sc.pl.umap and sc.pl.dotplot, and how their current arguments are organized. The issue provides example chained APIs but no files, tests, implementation plan, or precise acceptance criteria; done would require an agreed design and corresponding plotting-function changes.