Prep for v1.8.0 release

[untra]

🔤 Polyglot PR

• gemfile updates
• closes #142 #145 , adds tests for these
• site.xml and robots.txt solution
• readme updates including contributor section and callouts for cool folks
• v1.8.0 blogpost and variable prep

Type of change

• [x] Docs update (changes to the readme or a site page, no code changes)
• [ ] Ops wrangling (automation or test improvements)
• [ ] Bug fix (non-breaking change that fixes an issue)
• [x] New feature (non-breaking change that adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [x] Sweet release (needs a lot of work and effort)
• [ ] Something else (explain please)

Checklists

• [x] If modifying code, at least one test has been added to the suite