v1.2.3

Full Changelog: v1.2.2...v1.2.3

• Minor fix to the CITATION.md, CONTRIBUTING.md, README.md, and documentations.
• Added MAINTANENCE.md for maintanence plan.
• Added CODE_OF_CONDUCT.md principles for community engagements and collaborations.
• Added CHANGELOG.md
• Added new version.
• Fix bugs in retriever, pipeline, and rag modules.
• Added new dependencies and update version of setfit library.