Add some basic offchain metadata for Metadata section

Plus instructions to put it on githubusercontent.com. Eg: 

```
{
  "name": "Drew Coin",
  "symbol": "DREW",
  "description": "Token for Drew hodlers",
  "image": "https://fuchsia-formal-harrier-333.mypinata.cloud/ipfs/QmeYYLEjEa79w34RsDnCJjB6SWXYsho2kcigrWKdksbtSh"
}
```