Following from #148, it's clear that we need to revise the PHILOSOPHY.md file in the root of the repository. This needs to include information about:

1. The different groups of users we're targeting with the software (application developers, integrators, operators, etc.)
2. Our overall architectural approach
3. Possibly some mention of the differences between the philosophy of CometBFT and Tendermint Core, so users and open source developers are aware of this