Update stellar-keys.mdx

Author: janewang

cookbook/stellar-keys.mdx

@@ -50,6 +50,7 @@ Output:
 ```
 seed_phrase = "patrol clean public grocery roof aim have valve cherry dismiss lunar tail duty license capable little version banana amount often cover dice couple party"
 ```
+Note: The seed phrase is sensitive information. Handle it with care and never expose it publicly.
 
 ### 4. Derive the Secret Key
 
@@ -59,7 +60,7 @@ To display the secret key for the test identity:
 stellar keys secret test
 ```
 
-Example output:
+Output:
 ```
 SCJP663VYFZPYN75H2DYJA3FYUBP5UR23HZ4ZDHDMDY6TXVYUYMWNKTI
 ```
@@ -73,7 +74,7 @@ To display the corresponding public key for the test identity:
 stellar keys public-key test
 ```
 
-Example output:
+Output:
 ```
 GD3BFFX7DTNJAGDVVM5RYGGQQNURZTH4VSBLWF55YXY3L6T2WWZK57EI
 ```
@@ -86,7 +87,7 @@ This is the public address of your key.
 stellar keys fund test
 ```
 
-Example output:
+Output:
 ```
 ✅ Account test funded on "Test SDF Network ; September 2015"
 ```