doc: explain use of memory management annotation on strings
doc: explain use of memory management annotation on strings

Signed-off-by: Sven Verdoolaege <e5350bbed4977f5eb8ae1dc6abd9ae59d21ace75@kotnet.org>

BenzoSM/isl,Meinersbur/isl,inducer/isl-mirror,SaberMod/isl-current,evaautomation/isl,nicolasvasilache/isl,abduld/isl,Meinersbur/isl,inducer/isl-mirror,tobig/isl,BenzoSM/isl,nicolasvasilache/isl,BenzoSM/isl,PollyLabs/isl,UBERTC/isl,abduld/isl,nicolasvasilache/isl,Meinersbur/isl,KangDroidSMProject/ISL,UBERTC/isl,simbuerg/isl,UBERTC/isl,PollyLabs/isl,Distrotech/isl,simbuerg/isl,tobig/isl,BenzoSM/isl,PollyLabs/isl,tobig/isl,simbuerg/isl,KangDroidSMProject/ISL,KangDroidSMProject/ISL,inducer/isl-mirror,nicolasvasilache/isl,evaautomation/isl,tobig/isl,evaautomation/isl,nicolasvasilache/isl,Distrotech/isl,simbuerg/isl,SaberMod/isl-current,abduld/isl,inducer/isl-mirror,Distrotech/isl,SaberMod/isl-current,PollyLabs/isl,Distrotech/isl,UBERTC/isl,KangDroidSMProject/ISL,evaautomation/isl,SaberMod/isl-current,BenzoSM/isl,Meinersbur/isl,KangDroidSMProject/ISL,abduld/isl,PollyLabs/isl,Distrotech/isl,inducer/isl-mirror,simbuerg/isl