secrets remove all option (#8293)

Author: ykethan

src/pages/[platform]/deploy-and-host/sandbox-environments/features/index.mdx

@@ -86,14 +86,22 @@ value: abc123
 lastUpdated: Mon Nov 13 2023 22:19:12 GMT-0800 (Pacific Standard Time)
 ```
 
-### Remove secrets
+### Remove secret
 
 To remove a secret from from the sandbox, run the following command in your terminal:
 
 ```bash
 npx ampx sandbox secret remove foo
 ```
 
+### Remove all secrets
+
+To remove all secrets from the sandbox, run the following command in your terminal:
+
+```bash
+npx ampx sandbox secret remove --all
+```
+
 ### Reference secrets
 
 Once you have set a secret, you can reference the secret in your backend definition using the `secret()` function. The following example shows how to set up social sign-in with authentication in your app. Depending on your environment, Amplify will automatically load the correct secret value.

src/pages/[platform]/reference/cli-commands/index.mdx

@@ -174,6 +174,14 @@ If you want to remove a secret you previously set, use `sandbox secret remove`:
 npx ampx sandbox secret remove LOGINWITHAMAZON_CLIENT_ID
 ```
 
+#### Removing all secrets
+
+If you want to remove all secrets you previously set, use `sandbox secret remove --all`:
+
+```bash title="Terminal" showLineNumbers={false}
+npx ampx sandbox secret remove --all
+```
+
 #### Listing secrets
 
 List all available secrets for your personal sandbox in the default AWS profile and Region: