Include speed explanation

main.go

@@ -21,6 +21,8 @@ func init() {
 }
 
 func main() {
+	// If you wonder why this is slow, see how long even a very basic API request
+	// takes. swapi is very slow!
 	starships, err := AllStarships()
 	if err != nil {
 		log.Errorf("Error loading Starships: %+v", err)

swapi.go

@@ -7,6 +7,9 @@ import (
 	"sync"
 )
 
+// If you're using this module and wondering why it's slow, it's the API, not
+// this code.
+
 const API_PREFIX = "https://swapi.dev/api"
 
 // Source: https://swapi.dev/documentation#people