Create smart contracts

[Arshdeep54]

@Akshit517 @namay26

• Create Mapping [public key to display name ]
• Struct Post {display name , details about post , hash of the post (for ipfs)}
• Posts [mapped by display name ] contians all post
• create Post()
• Get allPost()
• Send Reward to contract ()- notify user to withdraw amount
• withdraw reward()
• Create a Data structure to manage friend and groups