Make proper usage documentation

[Privat33r-dev]

Rationale

Currently the Documentation part of the Readme refers to the video. Video format might be less than perfect choice by multiple reason:

• Accessibility: some people might have impaired hearing, while video has only autogenerated subtitles; others might not know language or have too slow internet connection
• Usability: it's hard to use a video as a quick cheatsheet/referral for the tool usage. Some people might need just a small refresher on certain part
• Maintainability: it's hard to edit video in case of changes

What should be included

• Detailed description of flags (like --no-ssl)
• Usage examples
• Best practices
• FAQ: common errors and their resolution