[nanovg] Add dependency port stb#8813

Merged

dan-shaw merged 5 commits intomicrosoft:masterfrom

JackBoosY:dev/jack/8809

Jan 6, 2020

Commits on Oct 30, 2019

[nanovg]Add depends port stb. Do not install stb headers.
JackBoosY
committed
[nanovg] Remove stb files from source to ensure the vcpkg-packaged copies are preferred.
ras0219-msft
committed

Commits on Nov 4, 2019