Add release notes summarizing breaking changes to SkRuntimeEffect

No-Try: true
Change-Id: I98f90add9ec3449a16ff40dfe833b124a98cc502
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/352507
Auto-Submit: Brian Osman <brianosman@google.com>
Reviewed-by: Heather Miller <hcm@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
1 file changed