docs(card): remove internal classes from docs (#3511)

Author: kara

src/lib/card/card.ts

@@ -8,6 +8,7 @@ import {
 
 /**
  * Content of a card, needed as it's used as a selector in the API.
+ * @docs-private
  */
 @Directive({
   selector: 'md-card-content, mat-card-content',
@@ -19,6 +20,7 @@ export class MdCardContent {}
 
 /**
  * Title of a card, needed as it's used as a selector in the API.
+ * @docs-private
  */
 @Directive({
   selector: 'md-card-title, mat-card-title',
@@ -30,6 +32,7 @@ export class MdCardTitle {}
 
 /**
  * Sub-title of a card, needed as it's used as a selector in the API.
+ * @docs-private
  */
 @Directive({
   selector: 'md-card-subtitle, mat-card-subtitle',
@@ -41,6 +44,7 @@ export class MdCardSubtitle {}
 
 /**
  * Action section of a card, needed as it's used as a selector in the API.
+ * @docs-private
  */
 @Directive({
   selector: 'md-card-actions, mat-card-actions',
@@ -52,6 +56,7 @@ export class MdCardActions {}
 
 /**
  * Footer of a card, needed as it's used as a selector in the API.
+ * @docs-private
  */
 @Directive({
   selector: 'md-card-footer, mat-card-footer',
@@ -63,6 +68,7 @@ export class MdCardFooter {}
 
 /**
  * Image used in a card, needed to add the mat- CSS styling.
+ * @docs-private
  */
 @Directive({
   selector: '[md-card-sm-image], [mat-card-sm-image]',
@@ -74,6 +80,7 @@ export class MdCardSmImage {}
 
 /**
  * Image used in a card, needed to add the mat- CSS styling.
+ * @docs-private
  */
 @Directive({
   selector: '[md-card-md-image], [mat-card-md-image]',
@@ -85,6 +92,7 @@ export class MdCardMdImage {}
 
 /**
  * Image used in a card, needed to add the mat- CSS styling.
+ * @docs-private
  */
 @Directive({
   selector: '[md-card-lg-image], [mat-card-lg-image]',
@@ -96,6 +104,7 @@ export class MdCardLgImage {}
 
 /**
  * Image used in a card, needed to add the mat- CSS styling.
+ * @docs-private
  */
 @Directive({
   selector: '[md-card-image], [mat-card-image]',
@@ -107,6 +116,7 @@ export class MdCardImage {}
 
 /**
  * Large image used in a card, needed to add the mat- CSS styling.
+ * @docs-private
  */
 @Directive({
   selector: '[md-card-xl-image], [mat-card-xl-image]',
@@ -118,6 +128,7 @@ export class MdCardXlImage {}
 
 /**
  * Avatar image used in a card, needed to add the mat- CSS styling.
+ * @docs-private
  */
 @Directive({
   selector: '[md-card-avatar], [mat-card-avatar]',
@@ -156,6 +167,7 @@ export class MdCard {}
 /**
  * Component intended to be used within the `<md-card>` component. It adds styles for a
  * preset header section (i.e. a title, subtitle, and avatar layout).
+ * @docs-private
  */
 @Component({
   moduleId: module.id,
@@ -173,6 +185,7 @@ export class MdCardHeader {}
 /**
  * Component intended to be used within the <md-card> component. It adds styles for a preset
  * layout that groups an image with a title section.
+ * @docs-private
  */
 @Component({
   moduleId: module.id,