Link color on site is inaccessible

[geoffrich]

The current color for links has a color contrast ratio of 3.53 against a white background, which could make it difficult for people with low vision to read. This fails the recommended WCAG minimum contrast ratio of 4.5.

I discovered this while working on other Axe accessibility issues I found on the Svelte docs (sveltejs/svelte#5678).

Since this is the primary color in the theme changing this could have wide-ranging effects. If we don't want to change this color, we could use a different color for links that passes the recommended contrast ratio threshold.

Example of link:

[geoffrich]

Also, the text color used for blockquotes on the docs does not have have sufficient contrast.

Example: