Feature/#155111428 - Visitor sees Landing Page (Section A)

[razwanizmi]

Pivotal Tracker Story ID: [#155111428]

Pre-Submission Checklist:

• Your pull request targets the master branch of calltocode.org
• Your branch is updated with the latest changes on master
• Your branch passes linting, building and all new and existing tests with command yarn test
• The story that this pull request addresses is referenced above by ID

Post-Submission Checklist:

• Your branch has no conflicts with master (find this out at the bottom of your pull request)
• Address any reviews on your pull request, as it will be unable to be merged until it is approved

Description of Changes:

Created Section A of landing page and pointed it to /landing-a.

[bbmoz]

Great job! I liked what you did with creating a brand new route for the section. Eventually, we want to combine the sections into a single page as the index.