SIMA spec for dotsama governance discussion data decentralization

We are OpenSquare team, currently dedicated to infrastructure building in the dotsama ecosystem, has developed and are maintaining products including subsquare, dotreasury, statescan, etc. We are proposing a specification to decentralize dotsame off-chain governance discussions data.

In current governance workflow, community users leave proposal context and have discussions in centralized platforms like Polkassembly, Subsquare, etc. Though usually these platforms have public APIs with which community members or other platforms can sync the data, there are still problems.

1. We can not verify the users' data. This is a common problem in web2 environment. Maybe these platforms have no motivations to tamper with the data, but we need more verification, less trust. So we can be 100% sure data belongs the owner.
2. Users' data maybe lost with a platform's misoperation, or a platform may just stop operations. We need a way to keep the data is always accessible.
3. Data should be more auditable. Currently, platforms don't save all the data modifications. User can modify the legacy leaved context, and the website will just show the context is updated, so users may not be able to see the old data which may include the proposal owner's commitments.
4. The more one signle centralized governance platform own users' data, the less possibility another platform can provide better solutions. We need a relatively decentralize data hosting solution which will not rely on single platforms or a dedicated group of people.
5. Differences of different platforms' API data format make it hard to sync and adapt all other platforms' data.

We propose SIMA spec to solve above problems. SIMA defines a set of user actions and data standards to decentralize off-chain governance data for substrate based blockchains. In general, with this spec governane users sign their actions data with their polkadot keys, submit the signed data to spec implementers. Spec implementers will be responsible for submitting the IPFS CID of user actions data to blockchain with a system#remark extrinsic.

It's still in draft status, and we'll be very appreciated with any suggestions. We will begin the development when the community reach some degree of consensus with its feasibility. Please check the full spec.