Rewrite Rule configuration intro and some minor copy edits. (#1799)
Rewrite Rule configuration intro and some minor copy edits. (#1799)

Signed-off-by: Stephen Gilson <2da87253ac69dd4a043b45f0beb918cbc6663db1@google.com>
istio/istio.io,istio/istio.io,linsun/istio.github.io,linsun/istio.github.io,istio/istio.io,geeknoid/istio.github.io,linsun/istio.github.io,geeknoid/istio.github.io,istio/istio.io,geeknoid/istio.github.io,geeknoid/istio.github.io,istio/istio.io,linsun/istio.github.io,linsun/istio.github.io,istio/istio.io,geeknoid/istio.github.io,istio/istio.io