File README.maintenance.md of Package powerline-rs

# How to update a rust package

## Prerequisites:

You need the `tar_scm`, `cargo_vendor` and `cargo_audit` obs services
installed:

    zypper in obs-service-tar_scm obs-service-cargo_vendor \
        obs-service-cargo_audit

## Updating to a new version from upstream

Edit the `_service` and `spec` file and update the version variable.

Download the new source file by running:

    osc service disabledrun

Update the changelog file with the upstream release notes.

Modified from https://build.opensuse.org/package/view_file/openSUSE:Factory/ripgrep/README.suse-maint.md