Document this as alternative UI

[friedger]

The repo description should link to 2d.monsteros.io

The README should

• explain that this is an alternative UI for the smart contract of monstereosio account.
• explain the limitations of the UI vs the current 3d version.

[leordev]

also important to say that at some point will be legacy....

like right now you can't battle... in the future you will probably be able only to feed/sleep/wake the pet...

new features are open chests, get items etc...