Regenerate data/docs.json

And add a note about `Delimiter` in mime types.

Closes https://github.com/gohugoio/hugo/issues/3615

content/extras/output-formats.md

@@ -28,6 +28,7 @@ This is the full set of built-in media types in Hugo:
 * It is possible to add custom media types or change the defaults (if you, say, want to change the suffix to `asp` for `text/html`).
 * The `Suffix` is the value that will be used for URLs and filenames for that media type in Hugo.
 * The `Type` is the identifier that must be used when defining new `Output Formats` (see below). 
+* The `Delimiter` defaults to ".", but can be changed or even blanked out to support, as an example, Netlify's `_redirect` files.
 * The full set of media types will be registered in Hugo's built-in development server to make sure they are recognized by the browser.
 
 To add or modify a media type, define it in a `mediaTypes` section in your site config (either for all sites or for a given language). 

data/docs.json

@@ -611,6 +611,21 @@
             ]
           ]
         },
+        "Uniq": {
+          "Description": "Uniq takes in a slice or array and returns a slice with subsequent\nduplicate elements removed.",
+          "Args": [
+            "l"
+          ],
+          "Aliases": [
+            "uniq"
+          ],
+          "Examples": [
+            [
+              "{{ slice 1 2 3 2 | uniq }}",
+              "[1 2 3]"
+            ]
+          ]
+        },
         "Where": {
           "Description": "Where returns a filtered subset of a given data type.",
           "Args": [