docs: review dir public staging guide (#336)

* fix(dir): environment setup for public staging

Signed-off-by: Catarina Paralta <[email protected]>

* fix(dir): federation request instructions

Signed-off-by: Catarina Paralta <[email protected]>

* refactor: delete sandbox and public staging documentation

Signed-off-by: Catarina Paralta <[email protected]>

---------

Signed-off-by: Catarina Paralta <[email protected]>

Author: paralta

docs/dir/.index

@@ -6,10 +6,6 @@ nav:
   - Trust Model: trust-model.md
   - Features and Usage: scenarios.md
   - Event Streaming: events.md
-  - Directory Sandbox:
-    - Directory Sandbox: directory-sandbox.md
-    - Public Staging Environment: directory-public-staging.md
-    - Deploying the Sandbox Environment: directory-sandbox-deployment.md
   - Hosted AGNTCY Agent Directory: hosted-agent-directory.md
   - CLI Reference: directory-cli.md
   - SDK Reference: directory-sdk.md