Add 'fern deep' command to CLI reference documentation

This commit introduces a new 'fern deep' command that allows users to email co-founder Deep directly from the CLI. The command includes optional --subject and --body flags to pre-fill email content, making it easier for users to reach out with questions, feedback, or support requests.

Changes:
- Added 'fern deep' to the main commands table
- Created detailed documentation section with usage examples
- Included command syntax and optional parameters

Author: fern-support

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

@@ -12,6 +12,7 @@ hideOnThisPage: true
 | [`fern upgrade`](#fern-upgrade) | Update Fern CLI & generators to latest versions |
 | [`fern login`](#fern-login) | Login to Fern CLI via GitHub or Google |
 | [`fern logout`](#fern-logout) | Log out of the Fern CLI |
+| [`fern deep`](#fern-deep) | Email our co-founder Deep |
 | [`fern export`](#fern-export) | Export an OpenAPI spec for your API |
 | [`fern api update`](#fern-api-update) | Manually update your OpenAPI spec |
 
@@ -387,6 +388,41 @@ hideOnThisPage: true
 
   </Accordion>
 
+  <Accordion title="fern deep">
+
+    Use `fern deep` to send an email to our co-founder Deep. This command opens your default
+    email client with a pre-addressed message to Deep for questions, feedback, or support.
+
+    <CodeBlock title="terminal">
+    ```bash
+    fern deep [--subject <subject>] [--body <message>]
+    ```
+    </CodeBlock>
+
+    Running this command without options will open your email client with Deep's email address pre-filled.
+
+    ### subject
+
+    Use `--subject` to pre-fill the email subject line.
+
+    ```bash
+    fern deep --subject "Question about SDK generation"
+    ```
+
+    ### body
+
+    Use `--body` to pre-fill the email message body.
+
+    ```bash
+    fern deep --body "Hi Deep, I have a question about..."
+    ```
+
+    <Tip>
+    You can combine both options to create a fully pre-filled email template.
+    </Tip>
+
+  </Accordion>
+
   <Accordion title="fern token">
 
     Use `fern token` to generate a `FERN_TOKEN` specific to your organization defined