[refactor,#59][s]: move packages/portal => examples/catalog as per plan in #59.

What is currently packages/portal is example of a running portal and should move to examples (it will get replaced by an actual portal lib soon).

examples/catalog/next.config.js

@@ -0,0 +1,48 @@
+const { PHASE_DEVELOPMENT_SERVER } = require('next/constants');
+
+module.exports = (phase, { defaultConfig }) => {
+  const dms = process.env.DMS;
+  const cms = process.env.CMS;
+  if (phase === PHASE_DEVELOPMENT_SERVER) {
+    if (dms) {
+      console.log('\nYou are running the app in dev mode 🌀');
+      console.log(
+        'Did you know that you can use mocked CKAN API? Just unset your `DMS` env var.'
+      );
+      console.log('Happy coding ☀️\n');
+    } else {
+      const mocks = require('./mocks');
+      mocks.initMocks();
+      console.log(
+        '\nYou have not defined any DMS API so we are activating the mocks ⚠️'
+      );
+      console.log(
+        'If you wish to run against your CKAN API, you can set `DMS` env var.'
+      );
+      console.log(
+        'For example, to run against demo ckan site: `DMS=https://demo.ckan.org`\n'
+      );
+    }
+
+    return {
+      i18n: {
+        locales: ['en', 'fr', 'nl-NL'],
+        defaultLocale: 'en',
+      },
+      publicRuntimeConfig: {
+        DMS: dms ? dms.replace(/\/?$/, '') : 'http://mock.ckan',
+        CMS: cms ? cms.replace(/\/?$/, '') : 'oddk.home.blog',
+      },
+    };
+  }
+  return {
+    i18n: {
+      locales: ['en', 'fr', 'nl-NL'],
+      defaultLocale: 'en',
+    },
+    publicRuntimeConfig: {
+      DMS: dms ? dms.replace(/\/?$/, '') : 'https://demo.ckan.org',
+      CMS: cms ? cms.replace(/\/?$/, '') : 'oddk.home.blog',
+    },
+  };
+};