[docs] Add guidance on ENVOY_BUG in STYLE.md (#14575)
[docs] Add guidance on ENVOY_BUG in STYLE.md (#14575)

* Add guidanceon ENVOY_BUG and macro usage to STYLE.md

Signed-off-by: Asra Ali <da4828c05ee1cc5a64445440d12151dedd1ac4a8@google.com>
lyft/envoy,lyft/envoy,envoyproxy/envoy,envoyproxy/envoy,lyft/envoy,envoyproxy/envoy,envoyproxy/envoy,envoyproxy/envoy,envoyproxy/envoy,envoyproxy/envoy,lyft/envoy,envoyproxy/envoy,envoyproxy/envoy,lyft/envoy,envoyproxy/envoy,envoyproxy/envoy,envoyproxy/envoy,lyft/envoy