Added profile images to posts feed on home page

• Used fetch() to load initial data for `posts` and `accounts`, so that don't have to re-fetch `accounts` data again if loading more posts via
• But using fetch() caused an warning "The client-side rendered virtual DOM tree is not matching server-rendered content." due to v-html for the post excerpt, so had to wrap to v-html

Remaining tasks: to add profile images to Top Streaks, Most Streaks, Featured Goals, Just Joined sidebars!