Use cash-market as the font

docs/css/app.css

@@ -1,3 +1,35 @@
+@font-face {
+    font-family: cash-market;
+    src: url("https://cash-f.squarecdn.com/static/fonts/cash-market/v2/CashMarket-Regular.woff2") format("woff2");
+    font-weight: 400;
+    font-style: normal
+}
+
+@font-face {
+    font-family: cash-market;
+    src: url("https://cash-f.squarecdn.com/static/fonts/cash-market/v2/CashMarket-Medium.woff2") format("woff2");
+    font-weight: 500;
+    font-style: normal
+}
+
+@font-face {
+    font-family: cash-market;
+    src: url("https://cash-f.squarecdn.com/static/fonts/cash-market/v2/CashMarket-Bold.woff2") format("woff2");
+    font-weight: 700;
+    font-style: normal
+}
+
+body, input {
+    font-family: cash-market,"Helvetica Neue",helvetica,sans-serif;
+}
+
+.md-typeset h1, .md-typeset h2, .md-typeset h3, .md-typeset h4 {
+    font-family: cash-market,"Helvetica Neue",helvetica,sans-serif;
+    line-height: normal;
+    font-weight: bold;
+    color: #353535;
+}
+
 button.dl {
   font-weight: 300;
   font-size: 25px;

mkdocs.yml

@@ -35,6 +35,7 @@ markdown_extensions:
   - tables
 
 nav:
+  - 'Overview': index.md
   - 'Calls': calls.md
   - 'Connections': connections.md
   - 'Recipes': recipes.md