Convert site to Hugo (#8316)

This commit converts content and layout to use Hugo.

layouts/partials/docs/content_page.html

@@ -0,0 +1,12 @@
+<p><a href="{{ printf "%s#%s" ("docs/editdocs" | relURL) .page.Path | safeURL }}" id="editPageButton">Edit This Page</a></p>
+{{ if not .page.Params.notitle }}
+<h1>{{ .page.Title }}</h1>
+{{ end }}
+{{ with .page.Params.content_template }}
+{{ partial . $ }}
+{{ else }}
+{{ if and (not .page.Params.toc_hide) (not (.page.HasShortcode "toc")) }}
+{{ .page.TableOfContents }}
+{{ end }}
+{{ .page.Content }}
+{{ end }}