Add a `.go` implementation of B+Tree (not binary tree)

[IAmRiteshKoushik]

[Aashiq-Edavalapati]

Hi, @IAmRiteshKoushik, @Ashrockzzz2003 I would like to take this issue if it comes under AMWOC

[Ashrockzzz2003]

You're already assigned to another issue. Complete it to take this up if it's free after tat.

[Shreya12125]

@IAmRiteshKoushik @Ashrockzzz2003 I would like to work on this issue since I have done a project on B+ trees before.

[Ashrockzzz2003]

Assigned @Shreya12125

[Shreya12125]

@Ashrockzzz2003 , Under which folder should I add this .go file?

[Ashrockzzz2003]

/non_linear/b+tree/b+tree.go