Specify expected UTF-8 encoding of metadata urls.

Author: MilkywayPirate

source/CIS/cis-2.rst

@@ -162,7 +162,7 @@ It is serialized as: the first 2 bytes encode the length (``n``) of the data, fo
 
 A URL and optional checksum for metadata stored outside of this contract.
 
-It is serialized as: 2 bytes for the length of the metadata url (``n``) and then this many bytes for the url to the metadata (``url``) (utf-8 encoded) followed by an optional checksum.
+It is serialized as: 2 bytes for the length of the metadata URL (``n``) and then this many bytes for the URL to the metadata (``url``) (UTF-8 encoded) followed by an optional checksum.
 The checksum is serialized by 1 byte to indicate whether a hash of the metadata is included, if its value is 0, then no content hash, if the value is 1 then 32 bytes for a SHA256 hash (``hash``) follows::
 
   MetadataChecksum ::= (0: Byte)