Add docs for addFieldFilter() function

Signed-off-by: David Arendsen <darendsen@gamepoint.com>

docs/functions/addFieldFilter.md

@@ -0,0 +1,43 @@
+# Flux Query Builder Docs
+
+## Functions » addFieldFilter()
+
+### Parameters:
+
+<table>
+  <tbody>
+    <tr>
+      <th>Name</th>
+      <th>Required</th>
+      <th>Data type</th>
+      <th>Description</th>
+    </tr>
+    <tr>
+      <td>fields</td>
+      <td>Yes</td>
+      <td>array</td>
+      <td>
+        The fields you want to have a filter on.
+      </td>
+    </tr>
+  </tbody>
+</table>
+
+
+### Example
+
+```php
+->addFieldFilter(['field1', 'field2'])
+```
+
+This will result in the following Flux function part:
+
+```
+|> filter(fn: (r) => 
+    r._field == "field1" or r._field == "field2"
+)
+```
+
+### Extra resources
+
+* [Flux documentation](https://docs.influxdata.com/flux/v0.x/stdlib/universe/filter/)

docs/functions/addReduce.md

@@ -38,12 +38,12 @@ use Arendsen\FluxQueryBuilder\Type\MathType;
 
 ```php
 ->addReduce([
-  [
-    'count' => new MathType('accumulator.count + 1'),
-  ],
-  [
-    'count' => 0,
-  ]
+    [
+        'count' => new MathType('accumulator.count + 1'),
+    ],
+    [
+        'count' => 0,
+    ]
 ])
 ```
 

docs/functions/from.md

@@ -26,10 +26,10 @@
 
 ```php
 ->from([
-  'bucket' => 'test_bucket',
-  'host' => 'https://us-west-2-1.aws.cloud2.influxdata.com',
-  'org' => 'example-org',
-  'token' => 'token'
+    'bucket' => 'test_bucket',
+    'host' => 'https://us-west-2-1.aws.cloud2.influxdata.com',
+    'org' => 'example-org',
+    'token' => 'token'
 ])
 ```