README.md: Add Rationale and link to rinstall blog post

Update README.md

Use outputdir as root for libraries in rust projects

Allow each install entry to be either a string or a struct

Update install.yml accordingly.

Apply cargo-clippy fixes

Update completions format in install.yml

Completions are now divided into bash, fish and zsh. There is no need
to specify the type for each completion file.

Add example in README.

Improve README format

Allow InstallEntry struct in completions

Update dependencies

Use "cargo metadata" to get target_directory in rust projects

main: Update .packaging to .package

CI: Disable unused dependencies check

Support install.yml file inside .package directory

README: Improve configuration section

Move default configuration in config directory

Update dependencies

Add builds.sr.ht CI

README.md: Update example and fix leading -

Add missing sources

package: Stop using the version when installing docs

Remove the now unused version from install.yml.