Add the apache license to the module-level comment

Author: adetokunbo

ascii-char/ASCII/Char.hs

@@ -6,6 +6,20 @@
 
 {- | The 'Char' type has 128 nullary constructors, listed in
     order according to each character's 7-bit numeric code.
+
+Copyright 2021 Chris Martin 
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
 -}
 module ASCII.Char (
   -- * The @Char@ type