enh: implement cleanup command (#34) * mod(rhino-pkg): Hotfix upgrade nala v0.14.0 has affected how upgrades work within Nala, as such we have had to apply some changes to rhino-pkg to accomodate. These flags have already existed in >=v0.13.0 and so are compatible with former versions of Nala according to @volitank * mod(rhino-pkg): Update version number Change to version v0.1.2 * ensure flatpack is sudo'ed * add cleanup option * Update README.md --------- Co-authored-by: ajstrongdev <adamjsalt@icloud.com>