v0.2.1 : Update defaults and new utilities

[C-Achard]

• Enable thresholding by default
• Enable window inference by default
• Add best thresholds values per-model
• Add new utility to grid-search best thresholds values
• Document new utility
• Version bump

[MMathisLab]

Let's bump to at least 0.2.1 since it has need features; could be 0.3.0

[C-Achard]

Let's bump to at least 0.2.1 since it has need features; could be 0.3.0

Done, thank you !