Add examples to versioning system (#493)

docs/contributing.md

@@ -20,6 +20,8 @@ After publishing a release, immediately update the version number to the next pa
 
 When releasing, remove the suffix and then publish.
 
+For example, let's say the last published version of `quickjs-wasm-rs` is `2.0.0`, so the current version in the Cargo.toml file is `2.0.0-alpha.1`. If you add a new public function, you would change the version to `2.1.0-alpha.1`. This is because adding a new public function is considered an additive change. After merging those changes, if you add a new public function, you would change the version to `2.1.0-alpha.2`. This is because adding another new function is an additional additive change. Now if you were to make a function that was public, private, you would change the version to `3.0.0-alpha.1`. This is because removing a public function is considered a breaking change. After merging that change, if you were to then add a new public function, then you would increment the version to `3.0.0-alpha.2` because this is making an additional additive change. It's not necessary to increment the minor version in this case because version `3.0.0` has not been published yet so version `3.0.0` can contain a mixture of additive and breaking changes from the last `2.x.x` version published.
+
 ## cargo vet
 
 We use [cargo vet](https://mozilla.github.io/cargo-vet/) to audit dependencies for the project. If you need to change or add dependencies, please try to use a dependency that has been audited by one one of the audits we import or is published by one of the authors we trust (sunfishcode, dtolnay, Amanieu, cuviper). This is preferable to adding new exemptions for the project. Do not add new audits for crates that are not in this project.