Relicense Promptkit under LGPL version 3 or later

README.md

@@ -65,4 +65,18 @@ Consumers moving from `v0.1.0` to `v0.2.0` should read the
 [Scriptorium](https://gitea.maximumdirect.net/eric/scriptorium) is the CLI and
 HTTP application built on Promptkit.
 
-Promptkit is licensed under the [GNU General Public License version 3](LICENSE).
+## License
+
+Promptkit is licensed under the [GNU Lesser General Public License version 3
+or later](LICENSE) (`LGPL-3.0-or-later`). The accompanying [GPLv3 text](COPYING)
+is incorporated by LGPLv3. This maintainer-authorized change applies from this
+revision forward; existing release tags and their license notices are unchanged.
+Dependencies, including the backend catalogs, retain their own licenses.
+
+Applications may use their own licenses subject to the LGPL's combined-work
+conditions. Distributors of statically linked Go binaries must account for the
+applicable notices, license copies, library source, and materials and permissions
+needed to recombine or relink with a modified library; installation information
+may also be required. Providing library source alone is not necessarily enough.
+See section 4 of the [LGPL text](LICENSE) for the governing requirements, rather
+than treating this summary as a complete distribution checklist.