Updates content on home page, menus, and scanner landing page

[hxlnt]

Changes include:

• Updates menus to combine "Try" and "Install sections" into one called "Get webhint"
• Updates copy on scanner landing page as part of scanner retirement
• Updates copy on home page and changes absolute links to relative links
• Adds some needed styles for new content

[hxlnt]

Note: I'll add a follow-up PR in the hint repo to update some of the docs in the User Guide.

[antross]

One question, but overall looks good and I like the updates. Thanks for putting them together!