Updates to the homepage

[wdower]

On the big "How MITRE SAF Works" component:

• make "hardening content library" ==> "automated hardening content library" and same for validation library on the homepage
• flip position of inspec_tools and vulcan in the validate column, tools row
• Add puppet to the list of automation tools along with Chef, Ansible, etc. -- might have to resize the images to get everything to fit nice -- use a light and a dark image for the site's light mode/dark mode