Mahati Shankar

added release notes for 2.10 and 2.11

1

**Description** Changes proposed in this pull request: - added release notes - minor grammatical changes in the text **Related issue(s)** Resolves #3692

clarify the difference between attributes and properties

3

**Description** Changes proposed in this pull request: - documentation suggested for the clarification between attributes and properties **Related issue(s)** Fixed #3848

**Description** Changes proposed in this pull request: - documentation suggested for the clarification between attributes and properties **Related issue(s)** Fixed https://github.com/SAP/luigi/issues/3848