Add current state for Node API

docs/api/v2/node.md

@@ -0,0 +1,27 @@
+# Node API
+
+TBD.
+
+*NOTE: Below is a scratch of what the API currently looks like. This will likely change. See https://github.com/status-im/nim-waku/issues/39*
+
+## Nim API
+
+*NOTE: Some of these are currently at the protocol layer rather than than the Node itself.*
+
+```
+method publish*(w: WakuSub, topic: string, data: seq[byte]) {.async.}
+method subscribe*(w: WakuSub, topic: string, handler: TopicHandler) {.async.}
+```
+
+## JSON RPC
+
+**TODO: Data should be RPC Messages / bytes**
+**TODO: Enable topic handler**
+
+Call sigs:
+
+```
+proc waku_version(): string
+proc waku_publish(topic: string, message: string): bool
+proc waku_subscribe(topic: string): bool
+```