Add highlights to overview scale bar

[cmdcolin]

Adding highlights to the overview scalebar could provide a nice global overview of your highlights

[MayaSatishRao]

@cmdcolin I wan to contribute to this issue. Can you please describe the issue in detail?

[MayaSatishRao]

@cmdcolin In the JBrowse demo I was able to bookmark a region and create a highlight. I want to know what is the overview scalebar. I have attached the picture of creating a highlight and can you point out what is the overview scalebar?

[cmdcolin]

@MayaSatishRao good question, this is the overview scalebar in the pic. it is an "overview" of the current chromosome you are looking at, so it shows the whole chromosome, while the lower area shows the specific region of the chromosome.

the motivation of this issue is to draw highlights in the "overview" as well as in the lower panel.