v2.1.0

Changelog

40c89c3 feat: configuration validation.
7c3bfd3 feat: improve comments on retry.
c7ed5dd feat: improve comments on retry.
6cbdb0c feat: improve errors handling.
86ad1b9 feat: improve message.
61d01c0 feat: simplify some algs.
74e00f0 feat: simplity clean labels on retry.
4634b3f fix: continue.
28d8c2c fix: update error.