Add new image for brand logo

[pconrad]

User Story

As a user I can see a cute brand icon so that I can feel awesome about the app.

Discussion

If you look at proj-ucsb-courses-search, and this https://github.com/ucsb-cs156-s21/proj-ucsb-courses-search/pull/227, you'll see that there is a cute logo in the "brand" spot.

In this issue, you'll add something similar for ucsb-cs-las.

We'll provide you with a link to the logo, and you'll make the changes so that it appears in the much thicker navbar (fixing the appearance of that is a separate story.)

Here is the new brand logo:

Note that the other PR was done incorrectly... the link should be a absolute link, not a relative one, so that the image still shows up when you navigate to other pages.

Acceptance Criteria

• [x] The logo should show up in the navbar on the home page
• [x] The logo should show up in the navbar on all pages

[WadeVaresio]

Closing as PR #213 addresses this issue.