TrainDB v2.5

What's Changed

• Feat: support synopsis-based approximate queries in standalone in #53
• Feat: IMPORT MODEL/SYNOPSIS ~ FROM FILE in 687f1d5 and 24bdcf6
• Feat: EXPORT MODEL/SYNOPSIS ~ TO FILE in 7c05de3 and a18123f
• Feat: CREATE SYNOPSIS ~ AS FILE / TABLE / DEFAULT in 830d733
• Fix: Query planning for complex join queries takes a long time in #51
• Docs: update README.md with the first logo image in 6464231
• Chore: add submodules to github actions in c0fbc8e
• Chore: add requirements.txt to the binary package in 54035cf
• Test: Add a TrainDB tutorial with python in Colab in 029f693

Full Changelog: 2.0...2.5