* DOC: add arXiv badge
* DOC: add Zenodo badge
* DOC: add caption to main `toctree`
* DOC: add LHCb logo
* DOC: add overview of main features
* DOC: collect links related to publication on welcome page
* DOC: import abstract to welcome page
* DOC: list Figure numbers next to download links
  Actually `setup.cfg` should list:
  ```ini
  [options.extras_require]
  doc =
      ...
      myst-parser >0.16.0  # field lists
      ...
  ```
  but this has not been done in the current PR as to avoid the constraint
  files from being updated.
* DOC: show only first level in left sidebar
  Looks better with the external links
* DOC: sync HTML short title with paper title
* FIX: add missing verb for downloading images