Update service-vs-library.md

`erros` => `errors`

Author: rrrutledge

service-vs-library.md

@@ -16,7 +16,7 @@ feature end-to-end: From the customer down to deployment, maintenance and
 support. This poses a challenge when working across team boundaries: Escalation
 chains may not be the same for errors happening in either team. Coupling
 source code and deployment leaves the teams with the question of who is
-responsible for on-call support in the event of erros. As a result teams are
+responsible for on-call support in the event of errors. As a result teams are
 reluctant to join forces even if there is significant overlap in requirements.
 
 ## Context