add SMI default values

[DaveSkender]

Adds SMI default values, according to related facioquo/stock-charts#269

Done when:

• use Blau’s “basic configuration” values for API defaults, per Stochastic Momentum Index (SMI) #625 (reply in thread)
• update documentation
• Update sample chart image

Checklist

• My code follows the existing style, code structure, and naming taxonomy
• I have put comments in my code, particularly for hard-to-understand areas
• I have performed a self-review of my code and included any verifying manual calculations
• I have added or updated unit tests that prove my fix is effective or that my feature works and achieves sufficient code coverage. New and existing unit tests pass locally and in the build (below) with my changes
• My changes generate no new warnings or other code analysis issues
• I have added or run the performance tests that depict optimal execution times
• I have made corresponding changes to the documentation