Outline permission docs structure (#9485)

Signed-off-by: Joon Park <joonp@spotify.com>

docs/permission/concepts.md

@@ -0,0 +1,5 @@
+---
+id: concepts
+title: Permission Framework Concepts
+description: A list of important permission framework concepts
+---

docs/permission/getting-started.md

@@ -0,0 +1,5 @@
+---
+id: getting-started
+title: Getting Started
+description: How to get started with the permission framework as an integrator
+---

docs/permission/overview.md

@@ -36,6 +36,6 @@ The permission framework was designed with a few key properties in mind:
 
 ## How do I get started?
 
-If you are a Backstage integrator, see the permission framework [documentation for adopters](./adopters/index.md).
+See the "[getting started](./getting-started.md)" permission documentation for Backstage integrators.
 
-If you are a plugin author, see the permission framework [documentation for plugin authors](./plugin-authors/index.md).
+If you are a plugin author, see the permission [documentation for plugin authors](../plugins/permissions/index.md) on how to integrate permissions into your plugin.

docs/permission/writing-a-policy.md

@@ -0,0 +1,5 @@
+---
+id: writing-a-policy
+title: Writing a permission policy
+description: How to write your own permission policy as a Backstage integrator
+---

docs/plugins/permissions/index.md

@@ -0,0 +1,5 @@
+---
+id: index
+title: Integrating Permissions into Plugins
+description: Learn how to integrate permissions into a Backstage plugin by following along with this Todo Plugin tutorial.
+---