As discussed in the team previously, to make it clearer for users, we want to mark a clear distinction between where the Tendermint Core ADRs/RFCs end and CometBFT ADRs/RFCs begin.

To this end, we aim to move the following directories around:

docs/architecture/* -> docs/architecture/tendermint-core/*
docs/rfc/*          -> docs/rfc/tendermint-core/*

We will start numbering CometBFT-specific ADRs and RFCs from 100 onwards, and will store them in the docs/architecture and docs/rfc folders.

Needs to be done for main and the v0.37.x branch. We still need to decide whether we'll maintain historical ADRs on the v0.34.x branch (it's probably a good idea if we're going to make any new architectural changes that affect that release series).