Import common steps into tutorials

[meaghanfitzgerald]

Some things are explained over and over in the docs (installing avalanche-cli, installing avalanche network runner, Avalanche Go). It is useful to have all necessary steps in one tutorial and not have the user jump from page to page. It would make sense to create one guide how to install avalanche-cli and then import this one over and over again. It can also be made collapsable, so it does not take up too much space and people can expand it, if they need the instructions.

This Docusaurus feature allows us to import .md files that have _ appended to the beginning: https://docusaurus.io/docs/markdown-features/react#importing-markdown

This thread demonstrates how to import a collapsible html element into an .md file: https://gist.github.com/joyrexus/16041f2426450e73f5df9391f7f7ae5f

We could go a step further, and create a custom react component that takes some params and returns this dropdown, making it easier for new documentation writers to include in their docs. but this is not necessary