Writing Conventions for Markdown-based Docs

When writing a "how-to" (_e.g: `learn-xyz`_) or general project documentation, should we have a list of writing conventions the way `O'Reilly` books (_the `benchmark` for tech books_) always have a "***Conventions Used in This Book***" section at the _start_ of the book e.g: http://www.oreilly.com/openbook/debian/book/prf1_02.html

## Terminal Commands

When instructing people to run a certain `command` in the `Terminal (Emulator)`, should we
+ include the `$` (_dollar sign_) in front of the command (_or not_) ? `#discuss`
+ _explicitly_ state that the command has to be run in the terminal?
+ use **`constant width bold`** for all "Commands or text to be typed by the user" ?

For a _complete_ list of the O'Reilly **Typography and Font Conventions**
see: http://chimera.labs.oreilly.com/books/1230000000969/ch03.html
PDF Snapshot: [O'Reilly-Typography-and-Font-Conventions.pdf](https://github.com/dwyl/contributing/files/573082/O.Reilly-Stylesheet-and-Word-List.pdf)