fix(ResourceCard-FeatureCard): icon was the wrong color

[sstrubberg]

Closes #883

Targeted the SVG in the ResourceCard and gave it icon-01. Update the FeatureCard docs to have one feature card using the default color and one feature card using dark mode.

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[vpicone]

Nice, I think carbon recently set the default icon color to be currentcolor. Since we very specifically only define the color of the title/subtitle, the svg gets the default anchor link color. I like that this implementation mirrors the dark one. Nice work!