feat: adding some Kafka concepts in diagram

.gitignore

@@ -0,0 +1 @@
+.idea

Makefile

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+run-kafka:
+	@docker exec -it fc2-kafka-kafka-1 bash

README.md

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+# Kafka basics and commands
+Prerequisite: make sure the Kafka broker is running and reachable at localhost:9092.
+
+## How to read the diagram (kafka.png)
+![Kafka overview](./kafka.png)
+
+## Delivery
+![Kafka delivery overview](./delivery.png)
+# Commands
+
+## Topics
+- Create a topic (3 partitions):
+```shell
+kafka-topics --create --topic test --bootstrap-server localhost:9092 --partitions 3
+```
+- List all topics:
+```shell
+kafka-topics --list --bootstrap-server localhost:9092
+```
+- Describe a topic (partitions/replicas/leader):
+```shell
+kafka-topics --describe --topic test --bootstrap-server localhost:9092
+```
+- Delete a topic:
+```shell
+kafka-topics --delete --topic test --bootstrap-server localhost:9092
+```
+
+## Console Producer
+- Write messages from stdin to a topic. Each line you type is a message:
+```shell
+kafka-console-producer --topic test --bootstrap-server localhost:9092
+```
+
+## Console Consumer
+- Read new messages from the tip of the log:
+```shell
+kafka-console-consumer --topic test --bootstrap-server localhost:9092
+```
+- Read everything from the beginning of the topic:
+```shell
+kafka-console-consumer --topic test --bootstrap-server localhost:9092 --from-beginning
+```
+- Join a consumer group (enables scaling and offset tracking):
+```shell
+kafka-console-consumer --topic test --bootstrap-server localhost:9092 --group group-x
+```
+
+## Consumer Groups
+- Describe a group (lags, offsets, assignments). Start at least one consumer in the group first:
+```shell
+kafka-consumer-groups --bootstrap-server localhost:9092 --group group-x --describe
+```

docker-compose.yaml

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-version: "3"
-
-services:  
-
+services:
   zookeeper:
     image: confluentinc/cp-zookeeper:latest
     environment: