docs/security: Separate documents under different subsection

docs/en/security/index.rst

@@ -2,11 +2,26 @@ Security Guides
 ***************
 :link_to_translation:`zh_CN:[中文]`
 
+Overview
+--------
 .. toctree::
    :maxdepth: 1
 
-   host-based-security-workflows
-   flash-encryption
    security
+
+Features
+--------
+.. toctree::
+   :maxdepth: 1
+
+   flash-encryption
    :esp32: secure-boot-v1
    secure-boot-v2
+
+Workflows
+---------
+.. toctree::
+   :maxdepth: 1
+
+   host-based-security-workflows
+

docs/zh_CN/security/index.rst

@@ -1,12 +1,27 @@
-安全指南
-********
+Security Guides
+***************
+:link_to_translation:`zh_CN:[中文]`
 
+Overview
+--------
 .. toctree::
    :maxdepth: 1
 
-   host-based-security-workflows
-   flash-encryption
    security
+
+Features
+--------
+.. toctree::
+   :maxdepth: 1
+
+   flash-encryption
    :esp32: secure-boot-v1
    secure-boot-v2
 
+Workflows
+---------
+.. toctree::
+   :maxdepth: 1
+
+   host-based-security-workflows
+