Introduce editorconfig

[the-spectator]

Description

This PR tries to partially address #623 by adding .editorconfig. Editorconfig helps to maintain consistent file formatting across various editors and IDEs.

Resource

Test process

• [x] Trims trailing spaces
• [x] Follows tabindent=2
• [x] Uses spaces instead of tabs. (Can be configured 😅 )

Requirements to merge

• [ ] 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 in hard-to-understand areas
• [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

[the-spectator]

@MattIPv4 I have updated according to your review and added editorconfig lint GitHub action.