Added and corrected comments

inlineXHTMLContent.go

@@ -12,6 +12,8 @@ type InlineXHTMLContent struct {
 	XHTMLDiv string `xml:"xhtmldiv"`
 }
 
+// newInlineXHTMLContent creates a new InlineXHTMLContent. It returns a
+// *InlineXHTMLContent and an error.
 func newInlineXHTMLContent(mediaType string, content any) (*InlineXHTMLContent, error) {
 	if mediaType != "xhtml" {
 		return nil, fmt.Errorf("media type %v incompatible with inline xhtml content", mediaType)
@@ -24,12 +26,19 @@ func newInlineXHTMLContent(mediaType string, content any) (*InlineXHTMLContent,
 	return &InlineXHTMLContent{Type: mediaType, XHTMLDiv: content.(string)}, nil
 }
 
+// isContent checks whether the InlineXHTMLContent is a Content. It returns a
+// bool.
 func (i *InlineXHTMLContent) isContent() bool { return true }
 
+// hasSRC checks whether the InlineXHTMLContent has a SRC attribute. It returns
+// a bool.
 func (i *InlineXHTMLContent) hasSRC() bool { return false }
 
+// getType returns the Type of the InlineXHTMLContent as a string.
 func (i *InlineXHTMLContent) getType() string { return i.Type }
 
+// Check checks the InlineXHTMLContent for incompatibilities with RFC4287. It
+// returns an error.
 func (i *InlineXHTMLContent) Check() error {
 	if i.Type != "xhtml" {
 		return errors.New("type attribute of inline xhtml content must be xhtml")