fix(docs): fix documentation (#5560)

Signed-off-by: ivan katliarchuk <ivan.katliarchuk@gmail.com>

Author: ivankatliarchuk

docs/tutorials/security-context.md

@@ -3,5 +3,5 @@
 You can run ExternalDNS with reduced privileges since `v0.5.6` using the following `SecurityContext`.
 
 ```yaml
-[[% include 'security-context/limited-privilege.yaml' %]]
+[[% include 'security-context/extdns-limited-privilege.yaml' %]]
 ```

mkdocs.yml

@@ -16,6 +16,7 @@ nav:
       - Out of Incubator: docs/20190708-external-dns-incubator.md
       - Code of Conduct: code-of-conduct.md
       - License: LICENSE.md
+      - Providers: docs/providers.md
   - Tutorials: docs/tutorials/*
   - Annotations:
     - About: docs/annotations/annotations.md
@@ -33,6 +34,7 @@ nav:
     - Rate Limits: docs/advanced/rate-limits.md
     - TTL: docs/advanced/ttl.md
     - FQDN Templating: docs/advanced/fqdn-templating.md
+    - Decisions: docs/proposal/0*.md
   - Contributing:
       - Kubernetes Contributions: CONTRIBUTING.md
       - Release: docs/release.md