[Issue #211] Updated README.md description for react-a11y-img-has-alt

closes #211

README.md

@@ -134,7 +134,7 @@ Rule Name   | Description | Since
 `prefer-type-cast`              | Prefer the tradition type casts instead of the new 'as-cast' syntax. For example, prefer '<string>myVariable' instead of 'myVariable as string'. Rule ignores any file ending in .tsx. If you prefer the opposite and want to see the 'as type' casts, then enable the tslint rule named 'no-angle-bracket-type-assertion'| 2.0.4
 `promise-must-complete`         | When a Promise instance is created, then either the reject() or resolve() parameter must be called on it within all code branches in the scope. For more examples see the [feature request](https://github.com/Microsoft/tslint-microsoft-contrib/issues/34). | 1.0
 `react-iframe-missing-sandbox`  | React iframes must specify a sandbox attribute. If specified as an empty string, this attribute enables extra restrictions on the content that can appear in the inline frame. The value of the attribute can either be an empty string (all the restrictions are applied), or a space-separated list of tokens that lift particular restrictions. You many not use both allow-scripts and allow-same-origin at the same time, as that allows the embedded document to programmatically remove the sandbox attribute in some scenarios. | 2.0.10
-`react-a11y-img-has-alt`        | Enforce that an `img` element contains the `alt` attribute or `role='presentation'` for decorative image. All images must have `alt` text to convey their purpose and meaning to **screen reader users**. Besides, the `alt` attribute specifies an alternate text for an image, if the image cannot be displayed. | 2.0.11
+`react-a11y-img-has-alt`        | Enforce that an `img` element contains the `alt` attribute or `role='presentation'` for decorative image. All images must have `alt` text to convey their purpose and meaning to **screen reader users**. Besides, the `alt` attribute specifies an alternate text for an image, if the image cannot be displayed. This rule accepts as a parameter a string array for tag names other than img to also check. For example, if you use a custom tag named 'Image' then configure the rule with: `[true, ['Image']]`<br/>References:<br/>[Web Content Accessibility Guidelines 1.0](https://www.w3.org/TR/WCAG10/wai-pageauth.html#tech-text-equivalent)<br/>[ARIA Presentation Role](https://www.w3.org/TR/wai-aria/roles#presentation) | 2.0.11
 `react-a11y-lang`               | For accessibility of your website, html elements must have a lang attribute and the attribute must be a valid language code.<br/>References:<br/>* [H58: Using language attributes to identify changes in the human language](https://www.w3.org/TR/WCAG20-TECHS/H58.html)<br/>* [lang attribute must have a valid value](https://dequeuniversity.com/rules/axe/1.1/valid-lang)<br/>[List of ISO 639-1 codes](https://en.wikipedia.org/wiki/List_of_ISO_639-1_codes) | 2.0.11
 `react-a11y-meta`               | For accessibility of your website, HTML meta elements must not have http-equiv="refresh". | 2.0.11
 `react-a11y-props`              | Enforce all `aria-*` attributes are valid. Elements cannot use an invalid `aria-*` attribute. This rule will fail if it finds an `aria-*` attribute that is not listed in [WAI-ARIA states and properties](https://www.w3.org/TR/wai-aria/states_and_properties#state_prop_def). | 2.0.11