Docs: enable ‘Edit this page’ (#280)

Signed-off-by: Carson Yang <yangchuansheng33@gmail.com>

docSite/layouts/docs/single.html

@@ -0,0 +1,34 @@
+{{ define "main" }}
+    <!-- override Prism's default copy messages to 'empty'. Required by CSS styling.
+         see: https://prismjs.com/plugins/copy-to-clipboard/#styling -->
+    <div data-prismjs-copy="" data-prismjs-copy-success="" data-prismjs-copy-error="">
+        {{ .Content }}
+    </div>
+
+    <!-- change -->
+    {{ if .Site.Params.docs.repoURL -}}
+        {{ partial (printf "%s/%s" ($.Scratch.Get "pathName") "gitinfo") . }}
+    {{ end -}}
+
+    {{ if .Page.Store.Get "hasMermaid" }}
+    <script type="module">
+        import mermaid from 'https://cdn.jsdelivr.net/npm/mermaid/dist/mermaid.esm.min.mjs';
+        const config = {
+            startOnLoad:true,
+            logLevel: "error",
+            align: "center",
+            theme:"null"
+        };
+        mermaid.initialize(config);
+    </script>
+    {{ end }}
+
+    {{ if .Site.Params.feedback.enabled | default false -}}
+        {{ if or (.Site.Params.plausible.dataDomain) (.Site.GoogleAnalytics) }}
+            {{- partial (printf "%s/%s" ($.Scratch.Get "pathName") "footer/feedback.html") . -}}
+        {{ else }}
+            {{ errorf "Either Google Analytics or Plausible Analytics must be configured before enabling the Feedback Widget." }}
+        {{ end }}
+    {{ end -}}
+
+{{ end }}