Add password to test vector section.

bip-0039.mediawiki

@@ -115,7 +115,10 @@ will make the desired wallet available.
 
 ==Test vectors==
 
-See https://github.com/trezor/python-mnemonic/blob/master/vectors.json
+The test vectors include input entropy, mnemonic and seed. The
+passphrase "TREZOR" is used for all vectors.
+
+https://github.com/trezor/python-mnemonic/blob/master/vectors.json
 
 ==Reference Implementation==