Dead links in docs

[derrickburns]

Error	URL	Anchor Text	Linked From
404 Not Found	https://www.getambassador.io/user-guide/istio	Istio	https://www.getambassador.io/docs/guides/
404 Not Found	https://github.com/datawire/ambassador/tree/master/end-to-end/ratelimit-service	simple rate limit service	https://www.getambassador.io/user-guide/rate-limiting-tutorial/
404 Not Found	https://www.getambassador.io/services/rate-limit-service	rate limiting service	https://www.getambassador.io/reference/rate-limits/
404 Not Found	https://www.getambassador.io/reference/running/diagnostics	diagnostics	https://www.getambassador.io/reference/running/
404 Not Found	https://github.com/datawire/ambassador/blob/master/templates/ambassador/ambassador-rbac-prometheus.yaml	ambassador-rbac-prometheus	https://www.getambassador.io/reference/statistics/
404 Not Found	https://www.getambassador.io/tutorials/github-sso/00-tenant.yaml	api-auth-with-github/00-tenant.yaml	https://www.getambassador.io/tutorials/github-sso/

[richarddli]

Thanks. I fixed the errant links to the istio and rate-limit-service. I couldn't find the other ones in a search through the tree. If you could PR them against the ambassador-docs repo, that would be great.

[devdattakulkarni]

Some more broken links on following page:
https://github.com/datawire/ambassador/blob/master/docs/concepts/overview.md