Update mentions of the license to LGPL instead of GPL since we changed

it a while ago.

README.md

@@ -38,7 +38,7 @@ Before you get started, make sure you're ok with signing the
 which will be needed before we accept your pull request. The goal is
 only to allow future relicensing without having to track down any past
 contributor, if such need were to arise. Note that the current license is
-GPLv3 and any contribution made today will remain available under that
+LGPL and any contribution made today will remain available under that
 license no matter what.
 
 ### Development setup
@@ -76,7 +76,7 @@ ocaml-tree-sitter is free software with contributors from multiple
 organizations. The project is driven by [r2c](https://github.com/returntocorp).
 
 - OCaml code developed specifically for this project is
-  distributed under the terms of the [GNU GPL v3](LICENSE).
+  distributed under the terms of the [GNU LGPL 2.1](LICENSE).
 - The OCaml bindings to tree-sitter's C API were created by Bryan
   Phelps as part of the reason-tree-sitter project.
 - The tree-sitter grammars for major programming languages are

tree-sitter.opam

@@ -4,7 +4,7 @@ authors: ["r2c"]
 homepage: "https://github.com/returntocorp/ocaml-tree-sitter"
 bug-reports: "https://github.com/returntocorp/ocaml-tree-sitter/issues"
 dev-repo: "git+https://github.com/returntocorp/ocaml-tree-sitter.git"
-license: "GPL-3.0-only"
+license: "LGPL-2.1"
 
 build: [
   ["./configure"]