Insert Montserrat font.

src/index.scss

@@ -1,10 +1,14 @@
 @import './colors.scss';
 
+@font-face {
+  font-family: 'Montserrat';
+  src: url(./fonts/Montserrat/Montserrat-Medium.ttf);
+}
+
 body {
   margin: 0;
-  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen',
+  font-family: 'Montserrat', 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu',
-    'Ubuntu', 'Cantarell', 'Fira Sans', 'Droid Sans', 'Helvetica Neue',
+    'Cantarell', 'Fira Sans', 'Droid Sans', 'Helvetica Neue', sans-serif !important;
-    sans-serif;
   -webkit-font-smoothing: antialiased;
   -moz-osx-font-smoothing: grayscale;
   background-color: $secondary !important;