ixa-v0.3.1

Added

• Changed Context::data_plugins into a Vec, implemented DataPlugin::index method. (#477)
• A justfile with a suite of tasks for local development. Implements #459. (#460)

Other

• Publicly exposed Context::get_execution_statistics. (#489)
• Added a chapter on indexing properties to the ixa book. (#449)
• bump release-plz/action from 0.5.108 to 0.5.110 (#479)