Adds addRangeFrom() method.

docs/functions/addRangeFrom.md

@@ -0,0 +1,41 @@
+# Flux Query Builder Docs
+
+## Functions » addRangeFrom()
+
+### Parameters:
+
+<table>
+  <tbody>
+    <tr>
+      <th>Name</th>
+      <th>Required</th>
+      <th>Data type</th>
+      <th>Description</th>
+    </tr>
+    <tr>
+      <td>from</td>
+      <td>Yes</td>
+      <td>string</td>
+      <td>Relative duration.</td>
+    </tr>
+  </tbody>
+</table>
+
+
+### Example
+
+```php
+->addRangeFrom( '-1h' )
+```
+
+This will result in the following Flux function part:
+
+```
+|> range(
+  start: -1h
+)
+```
+
+### Extra resources
+
+* [Flux documentation](https://docs.influxdata.com/flux/v0.x/stdlib/universe/range/)