- Removes the redundant "English" locale since English is the default
language when no locale is specified
- Adds translation tags to domain verification checker tool (so that one
broken link from there can be fixed)
- Fixes several typos in Japanese docs
- Adds redirects & other config changes to make links work
Also, rename "Get Started with the rippled API" to work better with the
framework and slightly restructure the page to provide more context (in
English).