Istanbul: There should have an explanation about colors and line numbers on the readme, gh-pages or on the report itself

[nighto]

Related to #111: What do the colors and the line numbers means?

So the meaning of the colors are explained on comments on this issue. But one might not know what do the numbers means (51, 18, 45 on the image above).

I think it should be on the README, on the gh-pages branch or on the report itself.

Thanks.

[ariya]

If your mouse cursor hovers around the colored area, there is a tool tip describing the meaning.

But I do agree, the color coding needs to be embedded in the report itself.

[jcollum]

there is a tool tip describing the meaning

Devs, you should put a legend of some sort on the index.html page. I had to come here to figure out what the I and E etc means.