Improve dual license wording in README

We are licensed under BSD or GPLv2. It is clear in our headers, but not in the README.

Fixes #3717

diff --git a/README.md b/README.md
index f91e68fdb108ce4d2273e69477954297fa7186c8..89857bf9bee2fd6273efb2c9f0896fc855e56915 100644 (file)
--- a/README.md
+++ b/README.md
@@ -5,7 +5,7 @@ targeting real-time compression scenarios at zlib-level and better compression r
 It's backed by a very fast entropy stage, provided by [Huff0 and FSE library](https://github.com/Cyan4973/FiniteStateEntropy).
 
 Zstandard's format is stable and documented in [RFC8878](https://datatracker.ietf.org/doc/html/rfc8878). Multiple independent implementations are already available.
-This repository represents the reference implementation, provided as an open-source dual [BSD](LICENSE) and [GPLv2](COPYING) licensed **C** library,
+This repository represents the reference implementation, provided as an open-source dual [BSD](LICENSE) OR [GPLv2](COPYING) licensed **C** library,
 and a command line utility producing and decoding `.zst`, `.gz`, `.xz` and `.lz4` files.
 Should your project require another programming language,
 a list of known ports and bindings is provided on [Zstandard homepage](https://facebook.github.io/zstd/#other-languages).
@@ -213,7 +213,7 @@ Zstandard is considered safe for production environments.
 
 ## License
 
-Zstandard is dual-licensed under [BSD](LICENSE) and [GPLv2](COPYING).
+Zstandard is dual-licensed under [BSD](LICENSE) OR [GPLv2](COPYING).
 
 ## Contributing