Rebuild docs to make them easier to maintain

_posts/2000-01-01-PubSubClient.md

@@ -0,0 +1,21 @@
+---
+tag: api
+type: constructor
+name: PubSubClient
+
+---
+
+Creates an uninitialised client instance.
+
+Before it can be used, it must be configured with the property setters:
+
+```
+EthernetClient ethClient;
+PubSubClient client;
+
+void setup() {
+    client.setClient(ethClient);
+    client.setServer("broker.example.com",1883);
+    // client is now configured for use
+}
+```