feat(ris): add support for direct image upload

[LuanRT]

Description

This adds support for direct image upload (as suggested by #31, thanks!).

Usage

const my_awesome_image = fs.readFileSync('./wow.png');
const reverse = await google.search(my_awesome_image, { ris: true });
console.info(reverse.results);

Type of change

• [x] New feature (non-breaking change which adds functionality)
• [x] This change requires a documentation update

Checklist:

• [x] My code follows the style guidelines of this project
• [x] I have performed a self-review of my own code
• [x] I have commented my code, particularly in hard-to-understand areas
• [x] I have made corresponding changes to the documentation
• [x] My changes generate no new warnings
• [ ] I have added tests that prove my fix is effective or that my feature works
• [x] New and existing unit tests pass locally with my changes
• [x] I have checked my code and corrected any misspellings