Move top-level docs into docs/ and tidy repo root (#7303)

Move BACKEND_README.md, DOCKER_QUICK_START.md, and IMPLEMENTATION_SPEC.md
into docs/. Move start-rustfs.sh into scripts/ and update config comments.
Drop stale fast.tar.gz and config/k3d/cluster.yaml.

Signed-off-by: Kevin Su <pingsutw@apache.org>

Author: pingsutw

README.md

@@ -135,7 +135,7 @@ uv pip install flyte[tui]
 
 ## Open Source Backend
 
-The open source backend for Flyte 2 is **coming soon**. This repository will contain the Kubernetes-native backend infrastructure for deploying Flyte 2 as a distributed, multi-node service. See the [Backend README](BACKEND_README.md) for the current state of the backend, protocol buffer definitions, and contribution guide.
+The open source backend for Flyte 2 is **coming soon**. This repository will contain the Kubernetes-native backend infrastructure for deploying Flyte 2 as a distributed, multi-node service. See the [Backend README](docs/BACKEND_README.md) for the current state of the backend, protocol buffer definitions, and contribution guide.
 
 If you need an enterprise-ready, production-grade backend for Flyte 2 today, it is available on [Union.ai](https://www.union.ai/try-flyte-2).
 
@@ -151,7 +151,7 @@ If you need an enterprise-ready, production-grade backend for Flyte 2 today, it
 
 ## Contributing
 
-We welcome contributions! See the [Backend README](BACKEND_README.md) for backend development, or join us on [slack.flyte.org](https://slack.flyte.org).
+We welcome contributions! See the [Backend README](docs/BACKEND_README.md) for backend development, or join us on [slack.flyte.org](https://slack.flyte.org).
 
 ## License
 

config/k3d/cluster.yaml

@@ -1,6 +1,6 @@
 # Flyte 2 Backend
 
-This repository contains the backend infrastructure for deploying a distributed, multi-node version of Flyte 2. The backend is **Kubernetes-native** — it orchestrates workflow execution using Kubernetes primitives, scheduling tasks as pods across clusters with built-in support for multi-cluster routing, service account-based identity, and pod-level log tracking. The core architecture consists of gRPC services (QueueService, RunService, StateService) backed by PostgreSQL, using async processing and real-time streaming via PostgreSQL LISTEN/NOTIFY. See the full [Implementation Spec](https://github.com/flyteorg/flyte/blob/v2/IMPLEMENTATION_SPEC.md) for details.
+This repository contains the backend infrastructure for deploying a distributed, multi-node version of Flyte 2. The backend is **Kubernetes-native** — it orchestrates workflow execution using Kubernetes primitives, scheduling tasks as pods across clusters with built-in support for multi-cluster routing, service account-based identity, and pod-level log tracking. The core architecture consists of gRPC services (QueueService, RunService, StateService) backed by PostgreSQL, using async processing and real-time streaming via PostgreSQL LISTEN/NOTIFY. See the full [Implementation Spec](https://github.com/flyteorg/flyte/blob/v2/docs/IMPLEMENTATION_SPEC.md) for details.
 
 This repo also defines the protocol buffer schemas for Flyte's APIs and generates client libraries for Go, TypeScript, Python, and Rust. Deploy this when you need Flyte running as a scalable, distributed service across your organization.
 

BACKEND_README.md docs/BACKEND_README.mdBACKEND_README.md renamed to docs/BACKEND_README.md

@@ -99,7 +99,7 @@ plugins:
       - _U_USE_ACTIONS: "1"
 
 # Storage Configuration
-# For local development, using RustFS (run: bash start-rustfs.sh)
+# For local development, using RustFS (run: bash ./scripts/start-rustfs.sh)
 # You can also use "mem" type for in-memory storage during testing
 storage:
   type: minio

DOCKER_QUICK_START.md docs/DOCKER_QUICK_START.mdDOCKER_QUICK_START.md renamed to docs/DOCKER_QUICK_START.md

@@ -33,7 +33,7 @@ logger:
   level: 4  # Info level
   show-source: true
 
-# Storage Configuration (for local dev, using RustFS — run: bash start-rustfs.sh)
+# Storage Configuration (for local dev, using RustFS — run: bash ./scripts/start-rustfs.sh)
 storage:
   type: minio
   container: "flyte-data"