adjust resource__menu svg

[harmon25]

Its me again! :D

I am using custom css for a more branded dark mode, since the svg fill is hard coded (as black) it is hard to see. This change uses a simpler svg that uses stroke="currentColor" which relies on the text color for the svg fill - which makes the color pretty trivial to change.

• uses the ellipsis-horizontal heroicon
• this uses currentColor to color with the text color css & allow overriding the default

It looks like this for me with a small CSS adjustment:

I think the default will be black (on the white bg)

[tfwright]

Looks great, thanks!