Handle dead links by copying and storing URL content into decentralized storage

[shanev]

1. Create IPLD links / hashes for all URL content (source / evidence, etc).

2. Store these on-chain.

3. When the user uploads content from the mobile app, we should generate these IPFS links on the client and store them on-chain.

4. Run our own IPFS node.

Eventually (could be post-MVP):

1. Cosmos should have an IPFS module by then (if not make one), and integrate it into truchain.

2. TruStory validators can also run IPFS nodes (or talk to a Cosmos IPFS zone).

[shanev]

Also keep an eye on https://github.com/irisnet/irisnet/blob/master/WHITEPAPER.md, who are creating a Cosmos Hub with IPFS built-in as a service. Could possibly leverage something there.