Add structs solution (#167)

Author: kawpii

internal/exercises/solutions/19_structs/structs.go

@@ -0,0 +1,10 @@
+package structs
+
+type Person struct {
+	Name string
+	Age  int
+}
+
+func NewPerson(name string, age int) Person {
+	return Person{Name: name, Age: age}
+}