Add old TAM homepage features

Description

When a user is logged out the TAM homepage displays some information about TAM and TAing. Most of this information was taken from the old TAM homepage (with some slight changes). Similarly, when a user is logged in and they click the TAM logo, they are taken to the homepage which displays some possible tasks (depending on the role).

Changes

• Add logged-out homepage text (mostly adapted from the old TAM homepage)
• Add logged-in homepage text (changes depending on role)

Related Issues

• Resolves #48 (closed)

src/main/resources/scss/_elements.scss

@@ -625,7 +625,7 @@
     margin-left: 2rem;
   }
 
-  @media(max-width: 1200px) {
+  @media(max-width: 75em) {
     flex-direction: column;
 
     & > .card {