Fix footer links and styles

[nam-m]

Some issues with the footer Previous PR: #83

UI

1. Links showing blue (instead of black) on deployed website (pointed out by @Unknown-0perator)
   • This can be Nextjs overwriting Link element's custom styles.
   • https://nextjs.org/docs/pages/api-reference/components/link#if-the-child-is-a-custom-component-that-wraps-an-a-tag.
2. The footer navigation links are underlined and Join Us is highlighted. We probably don't want this. I see that 'Join Us' is highlighted in Figma wireframe but it's probably only example of how every nav link should look like on hover.
3. Github and LinkedIn svg icons are not colored

4. The footer wrapper container has a visible line at border-top on the deployed web

   

   

Functionalities

1. No need to link OpenBC button since it directs to the homepage anyways
2. Subscribe, Terms of Service, Privacy Policy should not direct anywhere as they are not available yet. Maybe show a small dialog saying it is not available when getting clicked. The dialog should be positioned at the bottom and not intrusive
3. Contact Us might direct to OpenBC's email, check with Toki to make sure.

4. Footer is not at the bottom of the page on Join us and About pages