update pkgdown yml

_pkgdown.yml

@@ -4,4 +4,27 @@ template:
   bootswatch: lux
   params:
     ganalytics: G-20GDZ5LL77
-
+navbar:
+  bg: primary
+  title: timetk
+  left:
+  - icon: fa-home
+    href: index.html
+  - text: Start
+    href: articles/TK04_Plotting_Time_Series.html
+  - text: Articles
+    href: articles/index.html
+  - text: API
+    href: reference/index.html
+    menu:
+    - text: API Functions
+    - icon: fa-home
+      text: Function Reference
+      href: reference/index.html
+    - text: '---'
+    - text: Change History
+    - text: News
+      href: news/index.html
+  right:
+  - icon: fa-github
+    href: https://github.com/business-science/sweep