add docs for osc.message.filter processor

src/content/docs/processors/osc/message/filter.md

@@ -0,0 +1,15 @@
+---
+title: Decode
+sidebar:
+    order: 1
+---
+The `osc.message.filter` module takes an OSC message and matches it against a configured [OSC address pattern](https://opensoundcontrol.stanford.edu/spec-1_0.html). When the message does not match the payload of the processor will be set to `nil` result in the route being terminated. This processor will return an error if the OSC address pattern cannot be parsed.
+
+- **type**: `osc.message.filter`
+
+### Example
+```
+- type: osc.message.filter
+  params:
+    address: "/test/{a,b}/start"
+```