add json feed template for notes

layouts/notes/index.json

@@ -0,0 +1,21 @@
+{
+    "version": "https://jsonfeed.org/version/1.1",
+    "title": "{{ .Site.Title }} - Notes Feed",
+    "home_page_url": "{{ .Site.BaseURL }}",
+    "feed_url": "{{ .Permalink }}",
+    "description": "A feed of my notes from {{ .Site.Title }}",
+    "items": [
+        {{- range .Pages.ByDate.Reverse -}}
+        {
+            "id": "{{ .Permalink }}",
+            "url": "{{ .Permalink }}",
+            "content_text": {{ .Plain | jsonify }},
+            "date_published": "{{ .Date.Format "2006-01-02T15:04:05Z07:00" }}",
+            {{- if .Params.tags }}
+            "tags": {{ .Params.tags | jsonify }},
+            {{- end }}
+            {{- if not (last .Pages.ByDate.Reverse .) }},{{ end }}
+        }
+        {{- end }}
+    ]
+}