* reorganize files

1. make it easier to find files
2. reduce scrolling to get to README on main view of repo

* remove tr.txt again

* Add Spring Boot course, check_urls=free-courses-hi.md

* merge spring into Java

prefer not to create single item subcategories (also, isn't Spring Boot a subcategory of Spring? I haven't done Java or Spring for a while!)
Co-authored-by: NEric Hellman <eric@hellman.net>

* Added Ruby on Rails Book

Co-authored by: 17122 <72670008+17122@users.noreply.github.com>

* Fix line breaks.

* Fixed YouTube URL

* Update free-courses-hi.md

Added some more C++/Java Playlists.

* Update free-courses-hi.md

Changed the titles to original ones.

* Added course in android development by Harry

* Update free-courses-hi.md
Co-authored-by: NSeth <seth@elypia.org>
Co-authored-by: NSeth <seth@elypia.org>

Added new resource and fixed and arranged index and resources alphabetically. [Hacktober Fest] (#4510)

* Update free-courses-hi.md

* Listed the order alphabetically

* Added new Resource - Python

* Update free-courses-hi.md

Added Data Structures, and made some structural changes according to the guidelines.

* Update free-courses-hi.md

Updated the links in the Data Structures Topic.

* Update free-courses-hi.md

* Hindi language section added

* Hindi Free Courses Added

* Update free-programming-books-hn.md

* removed empty files
Co-Authored-By: NDwarkesh Kaswala <71209082+dwarcash@users.noreply.github.com>

* renamed hn to hi for hindi as per ISO
Co-Authored-By: NDwarkesh Kaswala <71209082+dwarcash@users.noreply.github.com>

* Hindi / हिंद language added
Co-Authored-By: NDwarkesh Kaswala <71209082+dwarcash@users.noreply.github.com>

* playlists removed and added one single video links
Co-Authored-By: NDwarkesh Kaswala <71209082+dwarcash@users.noreply.github.com>

* "playlist" links added and "full course in one video" links added
Co-Authored-By: NDwarkesh Kaswala <71209082+dwarcash@users.noreply.github.com>
Co-authored-by: NDwarkesh Kaswala <dwarkeshkaswala777@gmail.com>