fix: Navbar carets should never appear on a separate line (#369) (#530)

src/css/custom.scss

@@ -32,6 +32,7 @@
   // custom vars
   --electron-heading: var(--electron-color-mid);
   --electron-inline-code: var(--electron-color-secondary-mid);
+  --ifm-navbar-item-padding-horizontal: 8px;
 
   // docusaurus variables
   --ifm-hover-overlay: rgba(162, 236, 251, 0.2);