Some godoc adjustments and image struct renames

resources/page/pages.go

@@ -22,9 +22,11 @@ import (
 	"github.com/gohugoio/hugo/resources/resource"
 )
 
-// Pages is a slice of pages. This is the most common list type in Hugo.
+// Pages is a slice of Page objects. This is the most common list type in Hugo.
 type Pages []Page
 
+// String returns a string representation of the list.
+// For internal use.
 func (ps Pages) String() string {
 	return fmt.Sprintf("Pages(%d)", len(ps))
 }
@@ -37,7 +39,8 @@ func (ps Pages) shuffle() {
 	}
 }
 
-// ToResources wraps resource.ResourcesConverter
+// ToResources wraps resource.ResourcesConverter.
+// For internal use.
 func (pages Pages) ToResources() resource.Resources {
 	r := make(resource.Resources, len(pages))
 	for i, p := range pages {
@@ -86,10 +89,12 @@ func ToPages(seq any) (Pages, error) {
 	return nil, fmt.Errorf("cannot convert type %T to Pages", seq)
 }
 
+// Group groups the pages in in by key.
+// This implements collections.Grouper.
 func (p Pages) Group(key any, in any) (any, error) {
 	pages, err := ToPages(in)
 	if err != nil {
-		return nil, err
+		return PageGroup{}, err
 	}
 	return PageGroup{Key: key, Pages: pages}, nil
 }
@@ -100,6 +105,7 @@ func (p Pages) Len() int {
 }
 
 // ProbablyEq wraps compare.ProbablyEqer
+// For internal use.
 func (pages Pages) ProbablyEq(other any) bool {
 	otherPages, ok := other.(Pages)
 	if !ok {