Clarify the license of the included pythoncapi_compat.h header

The `pythoncapi_compat.h` header is distributed under the MIT license,
so include the full text of the license in the header and mention it in
the top level LICENSE file.

Fixes: #64

1 files changed, 20 insertions, 0 deletions

diff --git a/immutables/pythoncapi_compat.h b/immutables/pythoncapi_compat.h
index 5c661ab..fa6a960 100644
--- a/immutables/pythoncapi_compat.h
+++ b/immutables/pythoncapi_compat.h
@@ -3,6 +3,26 @@
 //
 // File distributed under the MIT license.
 //
+// Copyright Contributors to the pythoncapi_compat project.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+//
 // Homepage:
 // https://github.com/pythoncapi/pythoncapi_compat
 //