Add LinkedList Dart Lang: cosmos/code/data_structures/src/list/singly_linked_list

[Kweayon C.]

This is a(n):

• New algorithm
• [X ] Update to an existing algorithm
• Error
• Proposal to the Repository

Details:

[Kweayon C.]

@AdiChat please assign to me

[Atharva Thakur]

Please assign to me

[Kweayon C.]

@Atharva-Thakur I am already working on this and almost complete