Update README.md

[badj]

Finalised readme updates for feedback with the latest updates merged from upstream master.

Updated Readme with

1. Readme readability improvements
2. Hyperlink/embedding improvements
3. Contributor updates

Requesting approval from @star3am

NOTE: The previous PR was closed as some of the Jenkins updates from from hashiqube:master upstream master wasn't merged into my fork 🤦‍♂️

• [ ] 👎 / 👍 → ✅ → 🚀 : This PR has been created for approval for the most recent updates available to be merged into hashiqube:master upstream master after the latest changes from my fork were merged into hashiqube:master upstream master.

Testing notes

Smoke testing completed and passed

✅ Project building tests passed:

• [x] Without any errors reported during build* with: vagrant up --provision
• [x] All web apps starting up and accessible* as expected:

==> hashiqube0: Running provisioner: welcome (shell)...
    hashiqube0: Running: inline script
    hashiqube0: HashiQube has now been provisioned, and your services should be running.
    hashiqube0: Below are some links for you to get started.
    hashiqube0: Local documentation http://localhost:3333 Open this first.
    hashiqube0: Hashiqube status http://localhost:3001 and login with Username: admin and Password: P@ssw0rd
    hashiqube0: Online documentation https://hashiqube.com
    hashiqube0: Vault http://localhost:8200 with Initial Root Token: hvs.KADYQsHAZJtKIIu0vvvus4n8
    hashiqube0: Consul http://localhost:8500
    hashiqube0: Nomad http://localhost:4646

✅ Cross-browser testing completed for change-set:

• [x] Tested passed with the latest version of Chrome on Desktop and responsive for light and dark mode
• [x] Tested passed with the latest version of Firefox on Desktop and responsive for light and dark mode
• [x] Tested passed with the latest version of Safari on Desktop for light and dark mode