Add beginner-friendly documentation for ls command

[Anusha0501]

This PR adds beginner-friendly documentation for the ls command under linux/basics/.

[iamdevdhanush]

@Anusha0501 Thanks for the contribution and for taking the time to add beginner-friendly documentation for the ls command that effort is appreciated 👍

At the moment, I’m in the middle of restructuring the repository layout to introduce a level-based learning structure (Linux → Shell → Git → Docker → etc.). As part of this, the existing linux/basics/ path will be moved/renamed.

Because of this ongoing restructure, I’m going to hold off on merging new content PRs temporarily to avoid conflicts and rework.

Once the new structure is finalized, I’ll open clearly scoped issues (including Linux basics like ls) so contributions land in the correct place. You’re very welcome to contribute again at that point.

Thanks for understanding, and I appreciate your interest in contributing to the project.

[iamdevdhanush]

@Anusha0501 Please check again the structure of the repo has been changed completely.Love to contribute with you again!!