Add summary to readme

[ghost]

Adds a summary to the readme in order to make navigation easier by letting readers choose a specific topic of their interest instead of having to scroll all the way down searching for it

I've limited the summary nesting to two levels deep to avoid making it too extensive and defeating it's own purpose of facilitating the navigation

[ghost]

I just noticed now that GitHub already offers a table of contents to act as a summary, but i think that having a summary would still be useful due to the following reasons:

• It's platform-agnostic, that means if just in case this project gets hosted or migrates to some other Git provider in the future that doesn't offers a readme TOC, the summary would still be present
• Even though GitHub TOC provides a handy search input, it's window is somewhat small and unless you already know what you're looking for, it requires a bit of scrolling (still considerably less than scrolling the readme itself)

I'll leave this up to the maintainers to judge whether or not such addition would be necessary

[nanotee]

I used to do this when GitHub didn't have its auto-generated TOC but found it annoying to manually re-build the TOC every time I changed a heading. I'm in favor of leaving it as-is:

• I'm not worried about platform agnosticism because auto-generated TOCs are a pretty widely supported feature:
  • GitLab supports adding a [TOC]/[[_TOC_]] tag to insert it automatically
  • Visual Studio Code has an Outline View feature that supports Markdown
  • The preservim/vim-markdown plugin adds a :Toc command for Markdown files
• Browser extensions can turn HTML headings into a TOC, so you don't have to use the GitHub one:
  • Smart TOC
  • HeadingsMap

[ghost]

Got it, thanks for the quick response! :)