Update readme

[diptangsu]

Add information about other data structures

[sudeepta14]

I want to work on this @diptangsu

[KoustavCode]

Dude! gonna modify this.

[diptangsu]

@KoustavCode kor bhai ja khushi kor xD tor nijer i repo bhebe ne xD

[diptangsu]

@sudeepta14 Sure. Go ahead!

[Eduardogallegos]

@diptangsu working on this issue, is it ok?

[diptangsu]

@Eduardogallegos I haven't added this repo as part of hacktoberfest and I don't plan to either. But as long as I like what you add to this, I'll merge your PR. It's just that this repo is not maintained at all and I don't plan on working on this anytime soon.