Update 04MessageSchema.md

Revert `<choice>`

v1-0-RC3/doc/04MessageSchema.md

@@ -312,7 +312,7 @@ The `name` attribute of the `<choice>` uniquely identifies it.
 | sinceVersion         | Documents the version of a schema in which a choice was added                                                    | nonNegativeInteger | default = 0 |                                                                  |
 | deprecated           | Documents the version of a schema in which a choice was deprecated. It should no longer be used in new messages. | nonnegativeInteger | optional    | Must be less than or equal to the version of the message schema. |
 
-#### `< choice >` element content
+#### `<choice>` element content
 
 The element is required to carry a value, which is an unsigned integer
 representing a zero-based index to a bit within a bitset. Zero is the
@@ -558,4 +558,4 @@ Reserved element names
 | unit           | timestamp, TZ time          |
 | version        | messageHeader               |
 | week           | MonthYear                   |
-| year           | MonthYear                   |
+| year           | MonthYear                   |