Tizen reference link has been changed.
So, updated getting-started.md with the lastest link.
previous : https://source.tizen.org/documentation/reference/git-build-system/usage/gbs-build
updated : https://docs.tizen.org/platform/developing/building
Signed-off-by: Donghak PARK <donghak.park@samsung.com>
## Build on Tizen
-Get GBS from <https://source.tizen.org/documentation/reference/git-build-system/usage/gbs-build>
+Get GBS from <https://docs.tizen.org/platform/developing/building/>
First install the required packages.