Adjust spacing of section headers to account for nav bar (fix #986)

docs/public/css/base.scss

@@ -72,15 +72,25 @@ body {
 
 /* manual.liquid ******************************************/
 
-section {
-    padding-top: 24px;
-}
-
 h3 code {
     border: 0;
     font-size: 20px;
 }
 
+section {
+    /* Adjust spacing so that anchors are not hidden behind nav bar */
+    position: relative;
+    top: -50px;
+    padding-top: 50px;
+    margin-bottom: -50px;
+    h2 {
+        margin-top: 50px;
+    }
+    h3 {
+        margin-top: 32px;
+    }
+}
+
 @media(max-width: 991px){
     #navcolumn {
         /* Put nav column above manual content */