Convert docdock theme from submodule to native files and fix Hugo compatibility

themes/docdock/layouts/partials/flex/selectnavigation.html

@@ -0,0 +1,58 @@
+{{- $currentNode := . }}
+{{- if eq .Site.Params.ordersectionsby "title"}}
+  {{- range .Site.Home.Sections.ByTitle}}
+  {{- template "menu-nav" dict "sect" . "currentnode" $currentNode "level" 1}}
+  {{- end}}
+{{- else}}
+  {{- range .Site.Home.Sections.ByWeight}}
+  {{- template "menu-nav" dict "sect" . "currentnode" $currentNode "level" 1}}
+  {{- end}}
+{{- end}}
+
+<!-- templates -->
+{{- define "menu-nav" }}
+{{- $currentNode := .currentnode }}
+{{- $level := .level }}
+ {{- with .sect}}
+  {{- if .IsSection}}
+    <option value="{{ .RelPermalink}}" {{if eq .Permalink $currentNode.Permalink}} selected{{end}}>
+  {{if gt $level 1 }}
+    {{- range after 1 (seq $level)}}-{{ end }} 
+  {{end}} {{.Title}}</option>
+  
+  {{- if or (.IsAncestor $currentNode) (.Params.alwaysopen) }} <!-- dig into sub levels only if active or menu is always ON-->
+
+      {{- $numberOfPages := (add (len .Pages) (len .Sections)) }}
+      {{- if ne $numberOfPages 0 }}
+          {{- .Scratch.Set "pages" .Pages }}
+          {{- if .Sections}}
+          {{- .Scratch.Set "pages" (.Pages | union .Sections) }}
+          {{- end}}
+          {{- $pages := (.Scratch.Get "pages") }}
+
+        {{- if eq .Site.Params.ordersectionsby "title"}}
+          {{- range $pages.ByTitle }}
+            {{- if and .Params.hidden (not $.showhidden) }}
+            {{- else}}
+            {{- template "menu-nav" dict "sect" . "currentnode" $currentNode  }}
+            {{- end}}
+          {{- end}}
+        {{- else}}
+          {{- range $pages.ByWeight }}
+            {{- if and .Params.hidden (not $.showhidden) }}
+            {{- else}}
+            {{- template "menu-nav" dict "sect" . "currentnode" $currentNode "level" (add $level 1) }}
+            {{- end}}
+          {{- end}}
+        {{- end}}
+
+      {{- end}}
+  {{end}}
+  {{- else}}
+    {{- if not .Params.Hidden }}
+      <option value="{{ .RelPermalink}}" {{if eq .Permalink $currentNode.Permalink}} selected{{end}}> 
+{{- range after 1 (seq $level)}}-{{ end }} {{.Title}}</option>
+    {{- end}}
+  {{- end}}
+ {{- end}}
+{{- end}}