Adds State typedoc

lib/humiex/state.ex

@@ -25,6 +25,25 @@ defmodule Humiex.State do
   @type time() :: relative_time() | absolute_time()
   @type maybe_time() :: time() | nil
   @type event_id() :: String.t()
+
+  @typedoc """
+  A Humiex State struct
+  stores the client and query configuration alongside
+  execution metadata such as the latest seen event timestamp and event ids
+
+  - `:client` Humiex Client configuration
+  - `:query_string` Humio search API queryString
+  - `:start_time` Humio search API start time specification
+  - `:end_time` Humio search API end time specification
+  - `:opts` Keyword of additional options such as
+    - `:live?` uses a live query if set to `true`
+    - `:state_dest` allows to send the Humiex.State as a message to a process when using `stream_values/4`
+  - `:resp` Holds a reference to the Client that implements HTTPAsyncBehaviour and it's used to execute the requests
+  - `:last_timestamp` Last seen timestamp
+  - `:latest_ids` List of the seen event ids for the last timestamp
+  - `:event_count` Number of events returned so far
+  - `:chunk` Internal buffer used to hold the raw api responses before decoding the events
+  """
   @type t :: %__MODULE__{
           client: Client.t(),
           query_string: String.t(),