(api definitions) Add manual setup instructions for AsyncAPI (#808)

Author: devalog

fern/products/api-def/asyncapi-pages/overview.mdx

@@ -111,24 +111,67 @@ components:
 
 ## Set up your fern folder
 
-<Info> Considering options to generate an AsyncAPI spec? Get live support [here](https://fern-community.slack.com/join/shared_invite/zt-2dpftfmif-MuAegl8AfP_PK8s2tx350Q%EF%BB%BF#/shared-invite/email) </Info>
+<Info> 
+  Considering options to generate an AsyncAPI spec? Get live support [here](https://fern-community.slack.com/join/shared_invite/zt-2dpftfmif-MuAegl8AfP_PK8s2tx350Q%EF%BB%BF#/shared-invite/email) 
+</Info>
 
-Start by initializing your fern folder with an AsyncAPI spec
+<Steps>
+<Step title="Create your fern directory">
+Create a `fern/` folder in your project root.
 
-<CodeGroup>
-```sh file
-fern init --asyncapi ./path/to/asyncapi
 ```
-```sh url
-fern init --asyncapi https://host/path/to/asyncapi
+fern/
+```
+</Step>
+<Step title="Add your AsyncAPI specification">
+Add your AsyncAPI spec to the fern directory. You can place it in a subfolder called `asyncapi` or directly in the fern directory.
+
+```
+fern/
+  └─ asyncapi/
+    └─ asyncapi.yml
+```
+</Step>
+<Step title="Create a fern.config.json file">
+Add a `fern.config.json` file in your fern directory that lists your organization and the current version of the Fern CLI:
+
+```json title="fern.config.json"
+{
+    "organization": "your-organization",
+    "version": "0.77.2"
+}
 ```
-</CodeGroup>
 
-This will initialize a directory like the following 
+```
+fern/
+  ├─ fern.config.json
+  └─ asyncapi/
+    └─ asyncapi.yml
+```
+</Step>
+<Step title="Create a generators.yml file">
+Create a `generators.yml` file in your fern directory and add a reference to your AsyncAPI spec:
+
+```yaml title="generators.yml"
+# Your API definition
+api: 
+  specs: 
+    - asyncapi: ./asyncapi/asyncapi.yml
+
+groups:
+  external:
+    generators:
+      # Your generator configurations here
+```
+
+Your final directory structure:
+
 ```
 fern/
   ├─ fern.config.json
   ├─ generators.yml
   └─ asyncapi/
-    ├─ asyncapi.yml
-```    
+    └─ asyncapi.yml
+```
+</Step>
+</Steps>