Adds Hugo shortcode for content files to get data values

Hugo shortcode to access data file values within a content file. Set the data file, add an optional key (otherwise the entire file object will come back), and set the type to either count to get a count of the key's values or value to just get its value.

Shortcodes/getdata.html

@@ -0,0 +1,22 @@
+<!-- 
+  -- Hugo shortcode for content pages to access data file properties or counts
+  --
+  -- @param file    data file to reference in ./data
+  -- @param key     key in the data file object whose value you want
+  -- @param type    `count` to get a count of all items if an array, `value` to get the key's value 
+  --
+  -- {{% getdata file="icons.json" key="address-book" type="value" %}}
+  -->
+
+{{- $file := .Get "file" -}}
+{{- $key := .Get "key" -}}
+{{- $type := .Get "type" -}}
+{{- if eq $type "count" -}}
+    {{- if $key -}}
+        {{- (index .Site.Data $file $key) | len -}}
+    {{- else -}}
+        {{- (index .Site.Data $file) | len -}}
+    {{- end -}}
+{{- else -}}
+    {{- index .Site.Data $file $key -}}
+{{- end -}}