Adds new page for highlighting messages from leadership

- Adds a new page that shows the posts specifically from posts with the category leadership
- Adds this new page to the top navbar menu and news sidebar menu

Author: exoticDFT

_data/menus/news.yml

@@ -4,6 +4,8 @@
       link: /news/
     - name: Newsletters
       link: /newsletters/
+    - name: Messages from Leadership
+      link: /news/leadership/
     - name: Archive
       link: /archive/
     - name: Search

_data/navigation.yml

@@ -101,6 +101,8 @@
       link: newsletters
     - name: News and Updates
       link: news
+    - name: Messages from Leadership
+      link: news/leadership
     - name: News Archive
       link: archive
 - name: Resources

pages/posts/leadership.md

@@ -0,0 +1,16 @@
+---
+layout: page
+title: Statements from Leadership
+description: Messages from the Steering Committee and Executive Director
+permalink: /news/leadership/
+menubar: news
+---
+
+{% include scrolltop.html %}
+{% assign leadership = site.posts | where: "category", "leadership" %}
+{% for post in leadership %}{% assign currentDate = post.date | date: "%Y" %}{% if currentDate != myDate %}{% unless forloop.first %}</ul>{% endunless %}
+<h1 style="margin-top:20px; margin-bottom:10px">{{ currentDate }}</h1>
+  <ul>{% assign myDate = currentDate %}{% endif %}
+   <li><a href="{{ site.baseurl }}{{ post.url }}"><span>{{ post.date | date: "%B %-d, %Y" }}</span> - {{ post.title }}</a></li>
+   {% if forloop.last %}</ul>{% endif %}
+{% endfor %}