feat(demo): add landing page with docs (#1951)

docs/assets/ghspa.js

@@ -0,0 +1,54 @@
+/**
+ *
+ *  ____ _ ___ _  _ _  _ ___     ___  ____ ____ ____ ____    ____ ___  ____
+ *  | __ |  |  |__| |  | |__]    |__] |__| | __ |___ [__     [__  |__] |__|
+ *  |__] |  |  |  | |__| |__]    |    |  | |__] |___ ___]    ___] |    |  |
+ *
+ *  Easy way to enable Single Page Applications for GitHub Pages
+ *
+ *  This project was released under MIT license.
+ *
+ *  @link      https://github.com/rafrex/spa-github-pages
+ *  @author    Rafael Pedicini <code@rafrex.com>
+ *  @link      http://websemantics.ca
+ *  @author    Adnan M.Sagar, PhD. <adnan@websemantics.ca>
+ *
+ *  @param {Object} l, the document current location
+ *  @param {Boolean} projectPages, true by default, https://help.github.com/articles/user-organization-and-project-pages
+ *
+ */
+
+;(function(l, projectPages) {
+
+  var repo = projectPages ? '/' + l.pathname.split('/')[1] : '';
+
+  /* redirect all 404 trafic to index.html */
+  function redirect() {
+    l.replace(l.protocol + '//' + l.hostname + (l.port ? ':' + l.port : '') + repo + '/?' +
+      (l.pathname ? 'p=' + l.pathname.replace(/&/g, '~and~').replace(repo, '') : '') +
+      (l.search ? '&q=' + l.search.slice(1).replace(/&/g, '~and~') : '') +
+      (l.hash))
+  }
+
+  /* resolve 404 redirects into internal routes */
+  function resolve() {
+    if (l.search) {
+      var q = {};
+      l.search.slice(1).split('&').forEach(function(v) {
+        var a = v.split('=');
+        q[a[0]] = a.slice(1).join('=').replace(/~and~/g, '&')
+      });
+      if (q.p !== undefined) {
+        window.history.replaceState(null, null,
+          repo + (q.p || '') +
+          (q.q ? ('?' + q.q) : '') +
+          l.hash
+        )
+      }
+    }
+  }
+
+  /* if current document is 404 page page, redirect to index.html otherwise resolve */
+  document.title === '404' ? redirect() : resolve()
+
+}(window.location, window.projectPages || true ));