docs: introduce AsyncAPI document

pages/docs/concepts/asyncapi-document/_section.md

@@ -0,0 +1,4 @@
+---
+title: 'AsyncAPI Document'
+weight: 50
+---

pages/docs/concepts/asyncapi-document/index.md

@@ -0,0 +1,61 @@
+---
+title: 'Introduction'
+weight: 1
+---
+
+The AsyncAPI document is a YAML or JSON file that describes your implementation of the AsyncAPI specification. Providing a standardized way to document and describe asynchronous and event-driven systems, the AsyncAPI document generates documentation/code and defines the different components of your event-driven application, such as the events, channels, and message formats.
+
+Primarily, it provides a method to produce comprehensive, consistent, and standardized AsyncAPI documentation. Additionally, it serves as a contract for communication between consumers and producers in an event-driven system. It specifies what should be included in the payload when a service produces a message and provides information to the consumer about the properties in the message. 
+
+```YAML
+asyncapi: 3.0.0
+info:
+  title: Cool Example
+  version: 0.1.0
+channels:
+  user/signedup:
+    subscribe:
+      message:
+        description: An event describing that a user just signed up.
+        payload:
+          type: object
+          additionalProperties: false
+          properties:
+            fullName:
+              type: string
+            email:
+              type: string
+              format: email
+            age:
+              type: integer
+              minimum: 18
+```
+
+## AsyncAPI document components
+
+The AsyncAPI document follows a specific structure with certain headers or fields:
+
+- **`asyncapi`**: This is a required field that specifies the AsyncAPI specification version that your document adheres to.
+
+- **`info`**: This required field holds metadata about the API. The `info` section must include the following sub-fields:
+
+   - `title`: A descriptive title of the API.
+
+   - `version`: An API version identifier.
+
+   Optional fields within the `info` section could include `description`, `termsOfService`, `contact` (with subfields for `name`, `url`, `email`), and `license` (with `name` and `url` subfields).
+
+- **`servers`**: An optional field specifying the server(s) where the API is available. Each server must have a `url` and may have `protocol`, `protocolVersion`, `description`, `variables`, `security`, and `bindings`.
+
+- **`channels`**: This required field describes the paths available to the API and must include at least one channel. Each channel could include fields such as `description`, `subscribe`, `publish`, `parameters`, and `bindings`.
+
+- **`components`**: An optional section for defining reusable components like `messages`, `schemas`, `securitySchemes`, and others.
+
+- **`tags`**: An optional array of tags used by the specification with additional metadata. Each tag object can have `name` and `description`.
+
+- **`externalDocs`**: An optional section to provide more information, such as a link to the API’s external documentation with a `description` and a `url`.
+
+
+<Remember>
+You might have additional fields depending on the implemented protocol (i.e., MQTT, AMQP, Kafka, etc.).
+</Remember>