Mltraq

* Added utility steps `drop_fields` and `nothing`

* Fixed some quoting typos in the docs and code
* Added blog post on serializing a `Bunch` of things (blog/posts/009)
* Cleanup visibility of class methods and attributes (`_` and `__` prefix)
* Added PNG logo files with transparency for talks etc.

* Added slides from Munich MLOps Community Meetup 7, linked in the benchmarks/speed page
* Added notebooks/11 to experiment with the performance of different data storage options
* Added blog post on upstreaming experimental results (blog/posts/008)
* Renamed `session.load` to `session.load_experiment` and `session.persist` to `session.persist_experiment` for consistency

* Dropped `include_hidden` option support for archives, not supported by`glob.glob` in Python 3.10