docs: add jetstream configs and instructions

* add Makefile to replace bash script

docs/jetsream.md

@@ -0,0 +1,56 @@
+## NATS JetStream
+
+### Server setup
+
+- Enable `-js -sd`
+
+## Stream setup
+
+```go
+_, err = js.AddStream(&nats.StreamConfig{
+	Name:       streamName,
+    // Remove from JS once Acked (Should not be used with 1 consumer which acts as a  relayer e.g. Benthos).
+	// Retention:  nats.WorkQueuePolicy,
+    // MaxAge allows us to replay it within 48 hrs
+    MaxAge:     time.Hour * 48,
+	Storage:    nats.FileStorage,
+	Subjects:   []string{streamSubjects},
+    // Sliding window dedup period.
+	Duplicates: time.Minute * 5,
+})
+```
+
+## Producer
+
+```go
+// nats.MsgId is the unique identifier for dedup
+ctx.Publish("*", []byte("*"), nats.MsgId("*"))
+```
+
+## Consumer setup
+
+- Explicit ACK
+- Durable
+- Deliver: all
+
+### Benthos example
+
+```toml
+input:
+  label: jetstream
+  nats_jetstream:
+    urls:
+      - nats://127.0.0.1:4222
+    subject: "*"
+    durable: benthos
+    deliver: all
+  output:
+  stdout:
+    codec: lines
+```
+
+### Replay example
+
+```bash
+nats sub "*" --all --start-sequence=$N
+```