Docs: Versioning policy

README.md

@@ -342,6 +342,12 @@ This is in case you're relying on some functionality of a specific version of th
 
 In future, a mechanism for specifying an acceptable *range* of versions may be added to `class-extension`.
 
+## Versioning
+
+This module follows [semver](https://semver.org/). Breaking changes will only be made in major version updates.
+
+All active NodeJS release lines are supported (v10+ at time of writing). After a release line of NodeJS reaches end of life according to [Node's LTS schedule](https://nodejs.org/en/about/releases/), support for that version of Node may be dropped at any time, and this will not be considered a breaking change. Dropping support for a Node version will be made in a minor version update (e.g. 1.2.0 to 1.3.0). If you are using a Node version which is approaching end of life, pin your dependency of this module to patch updates only using tilde (`~`) e.g. `~1.2.3` to avoid breakages.
+
 ## Tests
 
 Use `npm test` to run the tests. Use `npm run cover` to check coverage.