update CI4 to 4.6.0 + use codeigniter-vite and vite-plugin-codeigniter to load assets

update php and js packages to latest

refactor migration queries to use forge functions

- use codeigniter4/tasks project to handle cron tasks
- use yassinedoghri/podcast-feed project to parse feeds for imports

update composer dependencies to latest

Users may choose between filesystem (FS) or S3 to store and manage their media files

closes #225

closes #222

- rename podlibre to adaures
- rename castopod-host to castopod
- simplify README and redirect to docs site
- move INSTALL and UPDATE docs
- add new gitlabci pipeline to deploy docs
- upgrade node to v16 in Dockerfile

update seed scripts to prevent sql error when reloading install page

feat(video-clip): generate video clips in the bg using a cron job + add video clip page + tidy up UI