[Feature Request] Annotations for setting ratelimit for ingress

[yue9944882]

Do you want to request a feature or report a bug?

feature

What did you expect to see?

I want to try out rate limiting features of traefik by simply adding annotations for kubernetes ingress instead of manually modifying toml configuration files:

• traefik.frontend.rateLimit.extractorFunc
• traefik.frontend.rateLimit.rateSet.burst
• traefik.frontend.rateLimit.rateSet.period
• traefik.frontend.rateLimit.rateSet.average

I think corresponding configurations for ratelimiting should be appended here at first

https://github.com/containous/traefik/blob/master/templates/kubernetes.tmpl

Any plan on this feature plz?

[ldez]

already done in #2612