docs(website): convert docs mobile nav from select to nav element and list (#1696)

* website: redo mobile nav to use Link and be rid of select input

* fix react className prop

* add zebapy to contributors

* website: upgrade gatsby deps to release candidate

* fix lint

website/src/css/imports/docs.css

@@ -21,43 +21,6 @@
       overflow-y: auto;
     }
 
-    &.mobile {
-      display: block;
-      position: relative;
-
-      @media screen and (min-width: $tablet) {
-        display: none;
-      }
-
-      &:after {
-        content: ' ';
-        position: absolute;
-        top: 7px;
-        right: 20px;
-        width: 0;
-        height: 0;
-        border-left: 5px solid transparent;
-        border-right: 5px solid transparent;
-        border-top: 5px solid $grey;
-        z-index: 3;
-      }
-
-      select {
-        border: none;
-        border-radius: $borderRadius !important;
-        cursor: pointer;
-        margin: -$medium auto $medium auto;
-        width: 100%;
-        position: relative;
-        padding: 14px 20px;
-        z-index: 2;
-        outline: none;
-        box-shadow: none;
-        -webkit-appearance: none;
-        -webkit-border-radius: 100px;
-      }
-    }
-
     .nav-link,
     .subnav-link {
       display: block;
@@ -236,3 +199,44 @@
   margin: 48px 0 0;
   line-height: 36px;
 }
+
+.mobile-docs-nav {
+  display: block;
+  position: relative;
+  margin-bottom: $small;
+
+  @media screen and (min-width: $tablet) {
+    display: none;
+  }
+}
+
+.mobile-docs-nav-btn {
+  display: block;
+  width: 100%;
+}
+
+.mobile-docs-nav-content {
+  /* border: 1px solid $lightishGrey; */
+  background-color: $lighterGrey;
+  padding: $tiny;
+}
+
+.mobile-docs-nav-list {
+  list-style: none;
+  margin: 0;
+
+  .mobile-docs-nav-list {
+    margin-left: $small;
+  }
+}
+
+.mobile-docs-nav-item {
+  font-weight: bold;
+  font-size: 14px;
+}
+
+.mobile-docs-nav-link {
+  font-size: 16px;
+  display: block;
+  padding: $micro;
+}