Create b+tree.c

[meltingOcean]

It is a code for b+tree. I have create insert operation and function that print whole of b+tree on tree shape.

[ayaankhan98]

• there is no main function?
• please be consistent with line spacing somewhere you have left 4 line space somewhere 2 lines and somewhere there is no space
• Add a main function
• Add a test function to test your code
• Add a proper Doxygen Style Documentaion with explaning everything you have done in the code.

[Panquesito7]

Please fix the braces position.
Make them look like:

if (var1 == var2) {
    // Something here

} else {
    // Something here
}