docs: add s3 remote state doc

docs/core-concepts/config.md

@@ -84,9 +84,11 @@ tools:
 
 ### State
 
-The `state` section specifies where to store DevStream state. As of now (v0.5.0,) we only support local "backend" to store the DevStream state. AWS S3 backend is being supported and will be released soon.
+The `state` section specifies where to store DevStream state. As of now (v0.5.0), we only support local backend.
 
-The `state` section has some options. For example, `stateFile` is mandatory for local backend.
+From v0.6.0 on, we will support both "local" and "s3" backend store the DevStream state.
+
+Read the section [The State Section in the Main Config](./stateconfig.md) for more details.
 
 ## Default Values
 

docs/core-concepts/stateconfig.md

@@ -0,0 +1,40 @@
+# The State Section in the Main Config
+
+In the main config, we can specify which "backend" to use to store DevStream state.
+
+We support the following types of backend:
+
+- local
+- s3
+
+## Local backend config example:
+
+```yaml
+varFile: variables-gitops.yaml
+
+toolFile: tools-gitops.yaml
+
+state:
+  backend: local
+  options:
+    stateFile: devstream.state
+```
+
+The `stateFile` under the `options` section is mandatory for local backend.
+
+## S3 backend config example:
+
+```yaml
+varFile: variables-gitops.yaml
+
+toolFile: tools-gitops.yaml
+
+state:
+  backend: s3
+  options:
+    bucket: devstream-remote-state
+    region: ap-southeast-1
+    key: devstream.state
+```
+
+The `bucket`, `region`, and `key` under the `ptions` section are all mandatory fields for s3 backend.

mkdocs.yml

@@ -24,7 +24,7 @@ nav:
     - 'core-concepts/core-concepts.md'
     - 'core-concepts/config.md'
     - 'core-concepts/variables.md'
-    - 'core-concepts/state.md'
+    - 'core-concepts/stateconfig.md'
     - 'core-concepts/dependencies.md'
     - 'core-concepts/output.md'
   - Plugins: