Added CODE_OF_CONDUCT.md

[Santhosh-Siddhardha]

Solved issue #2

Changes made are

• Added Pledge section
• Added Our Standards section
• Added Enforcement responsibilities section
• Added Scope section
• Added Enforcement Section
• Added Enforcement Guidelines Section

[Santhosh-Siddhardha]

@Ash515 Please add level label (likelevel1 or level2 or level3) to the issue. Only then this issue will be considered for my leaderboard.

[Santhosh-Siddhardha]

@Ash515 Please assign level label

[Santhosh-Siddhardha]

@Ash515 Please add level label and Please assign this PR to me