Fixed spelling/grammar error on es/02.1.md
Fixed spelling/grammar error on es/02.1.md

Errores de ortografía y gramática corregidos.
faxriddin/build-web-application-with-golang,songqii/build-web-application-with-golang,WangKaimin/build-web-application-with-golang,admpub/build-web-application-with-golang,astaxie/build-web-application-with-golang,songqii/build-web-application-with-golang,admpub/build-web-application-with-golang,admpub/build-web-application-with-golang,astaxie/build-web-application-with-golang,astaxie/build-web-application-with-golang,admpub/build-web-application-with-golang,faxriddin/build-web-application-with-golang,WangKaimin/build-web-application-with-golang