fix: exporting logo and better proptypes

package.json

@@ -2,8 +2,8 @@
   "name": "@edx/frontend-component-footer",
   "version": "1.0.0-semantically-released",
   "description": "Site footer component for use when building edX frontend applications",
-  "main": "dist/main.js",
-  "module": "dist/main.js",
+  "main": "dist/index.js",
+  "module": "dist/index.js",
   "publishConfig": {
     "access": "public"
   },

src/index.js

@@ -1,4 +1,5 @@
 import SiteFooter from './lib';
 
+export { default as FooterLogo } from './config/edx-footer.png';
 export { default as config } from './config';
 export default SiteFooter;

src/lib/SiteFooter.jsx

@@ -197,7 +197,7 @@ SiteFooter.propTypes = {
     src: PropTypes.node,
     altText: PropTypes.string,
     ariaLabel: PropTypes.string,
-  }),
+  }).isRequired,
   marketingSiteBaseUrl: PropTypes.string,
   linkSectionOne: linkSectionShape,
   linkSectionTwo: linkSectionShape,
@@ -245,13 +245,12 @@ const linkSectionDefault = {
 };
 
 SiteFooter.defaultProps = {
-  siteLogo: null,
   marketingSiteBaseUrl: null,
   linkSectionOne: linkSectionDefault,
   linkSectionTwo: linkSectionDefault,
   linkSectionThree: linkSectionDefault,
   socialLinks: [],
-  showMobileLinks: true,
+  showMobileLinks: false,
   appleAppStore: null,
   googlePlay: null,
   supportedLanguages: [],