Improvements to chart node in depth doc

[hwahlstrom]

Purpose

Improving chart node documentation for all six chart nodes based on findings from user testing. Improvements include clarifying confusing wording, adding more comprehensive information and examples, and describing input data in more detail.

Declarations

Check these if you believe they are true

• The codebase is in a better state after this PR
• Is documented according to the standards
• The level of testing this PR includes is appropriate
• User facing strings, if any, are extracted into *.resx files
• All tests pass using the self-service CI.
• Snapshot of UI changes, if any.
• Changes to the API follow Semantic Versioning and are documented in the API Changes document.
• This PR modifies some build requirements and the readme is updated
• This PR contains no files larger than 50 MB

Release Notes

Improved chart node in-depth documentation by adding more detail, providing examples, and clarifying input data structures

Reviewers

@QilongTang

FYIs

@Amoursol @lillismith