docs: remove RFC section and s/RFC001/ADR066 (#6345)

Per conversations earlier today, we'll consider all proposed implementation changes part of the ADR process rather than the RFC process (which will remain, for now, on the spec; this may get incorporated instead into the burgeoning "CIPS" process). 

This change renames RFC 1 to ADR 66, leaving space for the not-yet-merged ADR 65.

CONTRIBUTING.md

@@ -26,7 +26,8 @@ will indicate their support with a heartfelt emoji.
 
 If the issue would benefit from thorough discussion, maintainers may
 request that you create a [Request For
-Comment](https://github.com/tendermint/spec/tree/master/rfc). Discussion
+Comment](https://github.com/tendermint/spec/tree/master/rfc)
+in the Tendermint spec repo. Discussion
 at the RFC stage will build collective understanding of the dimensions
 of the problems and help structure conversations around trade-offs.
 

docs/architecture/README.md

@@ -84,3 +84,5 @@ Note the context/background should be written in the present tense.
 - [ADR-061-P2P-Refactor-Scope](./adr-061-p2p-refactor-scope.md)
 - [ADR-062-P2P-Architecture](./adr-062-p2p-architecture.md)
 - [ADR-063-Privval-gRPC](./adr-063-privval-grpc.md)
+- [ADR-064-Batch-Verification](./adr-064-batch-verification.md)
+- [ADR-066-E2E-Testing](./adr-066-e2e-testing.md)

docs/rfc/README.md

@@ -1,7 +0,0 @@
----
-order: 1
-parent:
-  order: false
----
-
-<!-- TODO: Add readme to RFC section -->