Yes. When you add a patch then increment the semver patch version number. When you add a public function then increment the semver minor version and reset the semver patch version to 0.
If you're doing something else, then you're not doing semver, and IMHO you should highlight that to your users.
Only if your version is greater than or equal to 1. Before that, you can do what you want.
Major version zero (0.y.z) is for initial development. Anything MAY change at
any time. The public API SHOULD NOT be considered stable.
> Initial development releases starting with "0.y.z" can treat changes in "y" as a major release, and "z" as a minor release. "0.0.z" releases are always major changes. This is because Cargo uses the convention that only changes in the left-most non-zero component are considered incompatible.
This makes it more useful for OSS that never seem to reach 1.0.