[DOCS BETA RELEASE] Fix @ember-data/model package is blank (#6444)

Author: Gaurav0

packages/model/addon/-private/attr.js

@@ -104,6 +104,9 @@ function hasValue(internalModel, key) {
   ```
 
   @method attr
+  @public
+  @static
+  @for @ember-data/model
   @param {String|Object} type the attribute type
   @param {Object} options a hash of options
   @return {Attribute}

packages/model/addon/-private/belongs-to.js

@@ -100,6 +100,9 @@ import { computedMacroWithOptionalParams } from './util';
   ```
 
   @method belongsTo
+  @public
+  @static
+  @for @ember-data/model
   @param {String} modelName (optional) type of the relationship
   @param {Object} options (optional) a hash of options
   @return {Ember.computed} relationship

packages/model/addon/-private/has-many.js

@@ -138,6 +138,9 @@ import { computedMacroWithOptionalParams } from './util';
   `ref.reload` to fetch the resources.
 
   @method hasMany
+  @public
+  @static
+  @for @ember-data/model
   @param {String} type (optional) type of the relationship
   @param {Object} options (optional) a hash of options
   @return {Ember.computed} relationship

packages/store/addon/-private/system/model/model.js

@@ -25,7 +25,7 @@ import { InvalidError } from '@ember-data/adapter/error';
 const { changeProperties } = Ember;
 
 /**
-  @module @ember-data/store
+  @module @ember-data/model
 */
 
 function findPossibleInverses(type, inverseType, name, relationshipsSoFar) {