docs: add adr about shared storages

doc/architecture/decision/007-refined-architect.md

@@ -21,3 +21,4 @@ It contains GitHub workflows, version management and Gradle helpers to help maki
 ## Consequences
 
 - Refined Storage adopts Refined Architect.
+- Refined Architect must be kept up to date and maintained in order to upgrade Refined Storage.

doc/architecture/decision/010-shared-storage.md

@@ -0,0 +1,43 @@
+# 10. Shared storages
+
+Date: 2024-03-03
+
+## Status
+
+Accepted
+
+## Context
+
+Refined Storage 2 has the concept of a storage channel. A storage channel is the highest-level storage of a network. It
+is used by other network devices to interact with the storage network.
+
+As Refined Storage 2 supports multiple resource types, we must decide how we partition those resource types.
+
+## Decision
+
+At the lowest level, we allow mixed resource types within a storage. Since a storage channel is a storage as well, this
+means that the highest level, the storage channel, will allow mixed resource types as well.
+
+We don't partition storages by resource type because:
+
+- This implies the use of a generic type on the `Storage` class, which becomes cumbersome quickly when we don't know the
+  resource type at runtime (relying on unchecked and rawtypes operations).
+- There's no real technical reason to partition storages by resource type. We can have a single storage channel with
+  mixed resource types.
+- If there is a single storage channel, blocks like the Disk Drive don't need to maintain a storage per storage channel.
+  They can expose one storage for all the storage channels, making it easier to reason about.
+
+Implementation provided in [[1]](#1).
+
+## Consequences
+
+- We do remove some compile time safety because we won't have a generic on `Storage`. However:
+    1) It's a natural consequence if we want to allow mixed storage channels.
+    2) The compile time safety was mostly gone anyway already due to all the unchecked and raw types operations.
+- We introduce `ResourceKey` to provide some level of safety (not using `Object`).
+- We don't need a storage channel type abstraction (there is only a single storage channel) and move some logic
+  to `ResourceKey`.
+
+## References
+
+- <a id="1">[1]</a> See [implementation](https://github.com/refinedmods/refinedstorage2/commit/1fd63d17417e387d427b2e018a93df89e31edc0f)