[ADF-4152] Restructured Content Services docs (#4429)

* [ADF-4152] Moved content services docs to subfolders

* [ADF-4152] Manual URL fixes for cont services docs

* [ADF-4152] Moved content services docs to subfolders

* [ADF-4152] Manual URL fixes for cont services docs

* [ADF-4152] Updated doc index pages for content services

docs/content-services/pipes/file-upload-error.pipe.md

@@ -0,0 +1,34 @@
+---
+Title: File upload error pipe
+Added: v3.0.0
+Status: Active
+Last reviewed: 2019-01-17
+---
+
+# [File upload error pipe](../../../lib/content-services/upload/pipes/file-upload-error.pipe.ts "Defined in file-upload-error.pipe.ts")
+
+Converts an upload error code to an error message.
+
+## Basic Usage
+
+<!-- {% raw %} -->
+
+```HTML
+<div>
+    Upload failed: {{ errorCode | adfFileUploadError }}
+</div>
+```
+
+<!-- {% endraw %} -->
+
+## Details
+
+The pipe takes an upload error code (eg, from the `error` event of one of the
+upload components) and converts it to a human-readable message. The message is
+automatically translated to the user's chosen language.
+
+## See also
+
+-   [File uploading dialog component](../components/file-uploading-dialog.component.md)
+-   [Upload drag area component](../components/upload-drag-area.component.md)
+-   [Upload button component](../components/upload-button.component.md)