updated indexes to include more

added keywords and better indexing of other elements

closes #290
modified to handle exception

made much less breakable and also classified keywords as part of SEO
updated readme to reflect search keywords
Merge branch 'develop' into slightly-better-search
Add count endpoint to newsletter/email

Closes #439
Merge pull request #445 from sendgrid/slightly-better-search

Slightly better search
Merge pull request #446 from sendgrid/develop

Deploy it