doc: fix synopsis for godoc (go-sql-driver#567)

Author: LionNatsu

AUTHORS

@@ -35,6 +35,7 @@ Kamil Dziedzic <kamil at klecza.pl>
 Kevin Malachowski <kevin at chowski.com>
 Lennart Rudolph <lrudolph at hmc.edu>
 Leonardo YongUk Kim <dalinaum at gmail.com>
+Lion Yang <lion@aosc.xyz>
 Luca Looz <luca.looz92 at gmail.com>
 Lucas Liu <extrafliu at gmail.com>
 Luke Scott <luke at webconnex.com>

driver.go

@@ -4,7 +4,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this file,
 // You can obtain one at http://mozilla.org/MPL/2.0/.
 
-// Package mysql provides a MySQL driver for Go's database/sql package
+// Package mysql provides a MySQL driver for Go's database/sql package.
 //
 // The driver should be used via the database/sql package:
 //