Add 'fern --dsheridan' command to CLI reference

Added documentation for the 'fern --dsheridan' flag that allows users to send
emails directly to Danny, one of Fern's co-founders. This follows the same
pattern as the existing --dsinghvi flag and includes:

- Command entry in the main commands table
- Complete accordion section with command syntax
- --message and --subject options documentation
- Multiple usage examples
- Helpful tip encouraging community engagement

Author: fern-support

fern/products/cli-api-reference/pages/commands.mdx

@@ -15,6 +15,7 @@ hideOnThisPage: true
 | [`fern export`](#fern-export) | Export an OpenAPI spec for your API |
 | [`fern api update`](#fern-api-update) | Manually update your OpenAPI spec |
 | [`fern --dsinghvi`](#fern---dsinghvi) | Send an email to Deep, our co-founder |
+| [`fern --dsheridan`](#fern---dsheridan) | Send an email to Danny, our co-founder |
 
 ## Documentation commands
 
@@ -635,4 +636,51 @@ hideOnThisPage: true
     </Tip>
 
   </Accordion>
+
+  <Accordion title="fern --dsheridan">
+
+    Use `fern --dsheridan` to send an email directly to Danny, one of our co-founders. Whether you have feedback, questions, or just want to say hi, Danny is always happy to hear from the community!
+
+    <CodeBlock title="terminal">
+    ```bash
+    fern --dsheridan [--message <your-message>] [--subject <subject>]
+    ```
+    </CodeBlock>
+
+    When run without options, this command will open your default email client with a pre-addressed message to Danny.
+
+    ### message
+
+    Use `--message` to include a specific message in your email.
+
+    ```bash
+    fern --dsheridan --message "Love the new SDK generation features!"
+    ```
+
+    ### subject
+
+    Use `--subject` to set a custom subject line for your email.
+
+    ```bash
+    fern --dsheridan --subject "Feature Request: GraphQL Support"
+    ```
+
+    ### Example usage
+
+    ```bash
+    # Open email client
+    fern --dsheridan
+
+    # Send a quick message
+    fern --dsheridan --message "Thanks for building Fern!"
+
+    # Send detailed feedback
+    fern --dsheridan --subject "Feedback on TypeScript SDK" --message "The generated types are excellent!"
+    ```
+
+    <Tip>
+    Danny loves hearing from users! Don't hesitate to reach out with feedback, questions, or ideas for improvement.
+    </Tip>
+
+  </Accordion>
 </AccordionGroup>