Add Page.GetTerms

Fixes #6905

resources/page/page.go

@@ -252,6 +252,10 @@ type PageWithoutContent interface {
 	maps.Scratcher
 	RelatedKeywordsProvider
 
+	// GetTerms gets the terms of a given taxonomy,
+	// e.g. GetTerms("categories")
+	GetTerms(taxonomy string) Pages
+
 	DeprecatedWarningPageMethods
 }
 

resources/page/page_nop.go

@@ -174,6 +174,10 @@ func (p *nopPage) GetParam(key string) interface{} {
 	return nil
 }
 
+func (p *nopPage) GetTerms(taxonomy string) Pages {
+	return nil
+}
+
 func (p *nopPage) GitInfo() *gitmap.GitInfo {
 	return nil
 }

resources/page/testhelpers_test.go

@@ -222,6 +222,10 @@ func (p *testPage) GetParam(key string) interface{} {
 	panic("not implemented")
 }
 
+func (p *testPage) GetTerms(taxonomy string) Pages {
+	panic("not implemented")
+}
+
 func (p *testPage) GetRelatedDocsHandler() *RelatedDocsHandler {
 	return relatedDocsHandler
 }