doc: cleanup release notes
doc: cleanup release notes

No-try: true
Change-Id: Ice2803974c7451aff200c75a609414cf9f0a17fe
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/245374
Auto-Submit: Hal Canary <fd9641b23487c8ee78406c27513624c460600766@google.com>
Reviewed-by: Heather Miller <2e22000c5d22374561fe5fba576a31095b72dc2e@google.com>
Commit-Queue: Hal Canary <fd9641b23487c8ee78406c27513624c460600766@google.com>

google/skia,google/skia,google/skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,HalCanary/skia-hc,HalCanary/skia-hc,aosp-mirror/platform_external_skia,google/skia,HalCanary/skia-hc,aosp-mirror/platform_external_skia,google/skia,HalCanary/skia-hc,google/skia,google/skia,HalCanary/skia-hc,google/skia,HalCanary/skia-hc,HalCanary/skia-hc,aosp-mirror/platform_external_skia,google/skia,aosp-mirror/platform_external_skia,google/skia,HalCanary/skia-hc,HalCanary/skia-hc,HalCanary/skia-hc