Liara

* Fix ``.yaml`` files with UTF-8 content not being read correctly. Now, files with a BOM are correctly recognized, and files without a BOM are assumed to be ``UTF-8`` encoded.
* Fix `Query` failure when a filter is used in conjunction with ``reverse``, but without specifying a sort order.
* Fix `readtime` ignoring the ``words_per_minute`` parameter.
* Fix ``validate-links`` failing on empty documents due to an incorrect assertion.

* Bump minimum Python version to 3.10.
* Improve log output for shortcodes. Use `--debug` to see information about each shortcode invocation.

* Provide the current node as a context variable to shortcode handlers.

* Rewrite the `ShortcodePreprocessor`. This resolves many issues with the existing preprocessor, for example:

* Quoted strings containing `/%>` are handled correctly now.
* Multiple shortcodes can be used in one line.
* No whitespace is needed before the closing tag.
* Non-quoted values can contain `-` now (previously, it was an alphanumeric characters or `_` only)
* Parsing robustness has generally improved with better error messages.

* Fix the `liara.signals.commandline_prepared` signal not specifying a `sender`, unlike all other signals.
* Improve documentation of signals & plugins.

* Add `exclude` and `include` to thumbnail definitions to skip creation of thumbnails for some images.