Add a section about statistical significance to the survey guidelines

[AndrejKiri]

Description

Statistical significance & confidence intervals help us communicate when users have to pay attention to differences in data and when we can omit them. We communicated it for the first time in the Collector follow-up survey. To be able to do it regularly, we should add guidelines on how to calculate statistical significance and confidence intervals and how to correctly communicate them.

Tasks

• Add content about calculating statistical significance to survey analysis guidelines
• Add content about communicating statistical significance to survey analysis guidelines

Links

• https://github.com/open-telemetry/sig-end-user/blob/main/end-user-surveys/analysis-guides/survey-analysis.md