Move State Retention docs to "Advanced Topics"

As State Retention is actually implemented by now, it's no longer just a
"Proposal".

1 files changed, 4 insertions, 4 deletions

diff --git a/web/input/doc/index.md b/web/input/doc/index.md
index 7b6a98a..1162124 100644
--- a/web/input/doc/index.md
+++ b/web/input/doc/index.md
@@ -23,6 +23,10 @@ These documents cover specific topics that go beyond the basics:
 * **[Extra-Opts][extra-opts]**  
   Telling plugins to read options from a configuration file.
 
+* **[State Retention Routines][retention-rfc]**  
+  Saving state information between plugin invocations.  Also see the
+  [FAQ entry][retention-api] on this topic.
+
 * **[Writing Perl Plugins][perl-plugins]**  
   This is a video that shows how to write your own check using the
   [Monitoring::Plugin][module] Perl module.
@@ -40,10 +44,6 @@ The following ideas are not yet implemented (and might never be):
 * **[Check Aggregation: check\_many][check-many]**  
   A plugin wrapper allowing aggregation and serialization of multiple checks.
 
-* **[State Retention Routines][retention-rfc]**  
-  Saving state information between plugin invocations.  This is actually
-  [implemented][retention-api] by now.
-
 [man]: doc/man/index.html "Manual Pages"
 [faq]: doc/faq/index.html "Frequently Asked Questions"
 [extra-opts]: doc/extra-opts.html "Extra-Opts"