splicectl: Support and Instructions for running on linux

Description

Updated readme with simpler installation instructions for installing splicectl on most major linux distributions.

With the new github actions for deploying updated splicectl packages, this will now make them more accessible.

All updated commands were manually tested on the command line.

If the pull request includes user-facing changes, extra documentation is required:

[ ] If the change is user facing, please ensure you add info in one of the Changelog Inclusions sections.

base feature note
- BREAKING note on base feature
- Basically whatever formatting we have here, just plain-text %> command example
next feature
- note on next feature