chore: update docs

[DaveSkender]

General documentation updates. No code changes.

To do:

• [x] add more instructions for developers in contributing.md
• [x] remove remote_theme: pages-themes/cayman@v0.2.0 templates, similar to .NET project
• [x] update general stylesheets similarly as well
• [x] replace use of jemoji gem and GitHub emoji syntax, in favor of plain ASCII emoji (see .NET project)
• [x] fix fonts on indicator pages

Checklist

• [x] My code follows the existing style, code structure, and naming taxonomy
• [x] I have commented my code, particularly in hard-to-understand areas
• [x] I have performed a self-review of my own code and included any verifying manual calculations
• [x] 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
• [x] My changes generate no new warnings and running code analysis does not produce any issues
• [x] I have added or run the performance tests that depict optimal execution times
• [x] I have made corresponding changes to the documentation

[DaveSkender]

@LeeDongGeon1996 my 2nd commit (https://github.com/DaveSkender/Stock.Indicators.Python/pull/330/commits/826f0eebdfd72b7e52148eddcc979a3712de860e) is an update to installation and setup guidance. I found that I needed to install openpyxl separately to get it to work. Is that something that should go into the requirements-test.txt file?

[LeeDongGeon1996]

@DaveSkender There are some Nuget page links on Code of Conduct.md and Security.md. If these are not intended, please fix them.

[DaveSkender]

@DaveSkender There are some Nuget page links on Code of Conduct.md and Security.md. If these are not intended, please fix them.

Those are intentional. It’s the only way I have right now to allow someone to privately communicate an issue without forcing them to connect through social media accounts, and without forcing me to publicly publish and email address for robots to pickup and spam.