Add colors to summary

[limdingwen]

Uses the existing intervalColor function. Includes documentation consistent with CmdTags and CmdChart.

Closes #459.

[limdingwen]

Hang on, realised this doesn't correctly handle cases where the tag has no color.

Documenting down differences in color handling logic:

• Tags: Only one allowed, no color if empty
• Summary: Multiple allowed, no color if empty
• Chart: Multiple allowed, show palette color if empty

Because of this, I'll need to adapt the logic from intervalColor slightly to accommodate Summary.

Edit: Implementation screenshot

[limdingwen]

I'm unable to test if the code works with color = off, due to bug #464, but from the code it seems that CmdTags does not check that flag when displaying colors?

Edit: On second look, it seems like color is intended to only affect theme colors, not tag colors.

[limdingwen]

The PR is ready to be reviewed! 😄

Not sure what's with the GH tests, it worked on the previous commit :P This commit literally only added 2 whitespaces to fix the formatting

[lauft]

LGTM 👍🏻

[lauft]

Not sure what's with the GH tests, it worked on the previous commit :P This commit literally only added 2 whitespaces to fix the formatting

The error in the previous run were due to another issue (already fixed) connected with the execution time. See 👉🏻 #466