add doc index.html and combined pdf

Author: bqminh

doc/index.html

@@ -0,0 +1,45 @@
+---
+layout: doc
+title: Documentation
+doctypes:
+  - tutorial
+  - manual
+---
+
+<div class="container mtb">
+    <div class="row">
+        <div class="col-sm-10 col-sm-offset-1 col-md-8 col-md-offset-2">
+            <div class="list-group">
+                <div class="list-group-item list-group-item-success centered">
+                <h4><a href="iqtree-doc.pdf"><i class="fa fa-file-pdf-o fa-2x" aria-hidden="true"></i> IQ-TREE Tutorials and Manual in one PDF</a></h4>
+                </div>
+            </div>
+        </div>
+    </div>
+    <div class="row">
+        {% for dt in page.doctypes %}
+        <div class="col-sm-6">
+            {% assign sorted_posts = site.pages | where: 'doctype', dt | sort: 'docid' %}
+            {% for post in sorted_posts %}
+            <!-- Document -->
+            <div class="well">
+                <h2>{{ post.title }}</h2>
+                <p>{{ post.description }}</p>
+                {% if post.sections %}
+                    <ul>
+                    {% for section in post.sections %}
+                      {% if post.sections_new_page %}
+                      <li><a href="{{ post.url | prepend: site.baseurl }}{{ section.url }}">{{ section.name }}</a></li>
+                      {% else %}
+                      <li><a href="{{ post.url | prepend: site.baseurl }}#{{ section.url }}">{{ section.name }}</a></li>
+                      {% endif %}
+                    {% endfor %}
+                    </ul>
+                {% endif %}
+                <p><a href="{{ post.url | prepend: site.baseurl }}" class="btn btn-primary" role="button">&#8594; Read All {{post.title}} Here</a></p>
+            </div>
+            {% endfor %}
+        </div>
+        {% endfor %}
+    </div><!--/row -->
+</div><!--/container -->