* Move the config variables which could be specified as tables in TOML
to the bottom of the documentation, to avoid that a regular toplevel
variable is used below them (which would be wrong in TOML).
* Be more specific about the value of the `upload_limit`.
* Adjust provider and aggregator to copy the used openpgp pubkey into a locally
provided directory `openpgp` beside the `prodiver-metadata.json`.
This more robust and self-reliant than using a public pubkey server,
which is the reason why the CSAF 2.0 csd02 mentions it as example in
"7.1.20 Requirement 20: Public OpenPGP Key".
* Improve aggregator by removing a typo `aggreator` from one written paths.
(Done with this change as it also affects the openpgp/ paths writing.)
solve #85
* Add short description for each component in the main README
* Move more Info in separated files.
* Add hint that csaf_provider offers a service interface.
* Explain why windows only has uploader and checker.
Co-authored-by: Bernhard Reiter <bernhard@intevation.de>
