Update docs of secrets set command

docs/cli/commands/secrets.mdx

@@ -186,12 +186,28 @@ This command allows you to set or update secrets in your environment. If the sec
 If the secret key does not exist, a new secret will be created using both the key and value provided.
 
 ```bash
-$ infisical secrets set <key1=value1> <key2=value2>...
+$ infisical secrets set <key1=value1> <key2=value2> <key3=@/path/to/file>...
 
 ## Example
-$ infisical secrets set STRIPE_API_KEY=sjdgwkeudyjwe DOMAIN=example.com HASH=jebhfbwe
+$ infisical secrets set STRIPE_API_KEY=sjdgwkeudyjwe DOMAIN=example.com HASH=jebhfbwe SECRET_PEM_KEY=@secret.pem
 ```
 
+  <Tip>
+    When setting secret values:
+      - Use `secretName=@path/to/file` to load the secret value from a file
+      - Use `secretName=\@value` if you need the literal '@' character at the beginning of your value
+
+    Example:
+
+    ```bash
+    # Set a secret with the value loaded from a certificate file
+    $ secrets set CERTIFICATE=@/path/to/certificate.pem
+
+    # Set a secret with the literal value "@example.com"
+    $ secrets set email=\@example.com
+    ```
+  </Tip>
+
 ### Flags
 
   <Accordion title="--env">