Add markup renderers

Signed-off-by: Nikolaos Karaolidis <nick@karaolidis.com>

layouts/_default/_markup/render-heading.html

@@ -0,0 +1,4 @@
+<h{{ .Level }} id="{{- .Anchor | safeURL -}}" class="heading">
+  {{ .Text | safeHTML }}
+  <a href="#{{- .Anchor | safeURL -}}" class="heading-anchor">#</a>
+</h{{ .Level }}>

layouts/_default/_markup/render-image.html

@@ -0,0 +1,6 @@
+{{ partial "image.html" (dict
+  "path" .Destination
+  "caption" .Text
+  "alt" .Title
+  )
+}}

layouts/_default/_markup/render-link.html

@@ -0,0 +1,9 @@
+<a
+  href="{{- .Destination | safeURL -}}"
+  {{ with .Title }}title="{{- . -}}"{{ end }}
+  {{ if strings.HasPrefix .Destination "http" }}
+    target="_blank" rel="noopener"
+  {{ end }}
+>
+  {{ .Text | safeHTML }}
+</a>