Import "State Retention" page from old web site

Add Ton's "State Retention" RFC to the list of "Proposals" (even though
it has been implemented and documented¹ by now).

¹ https://www.nagios-plugins.org/doc/faq/private-c-api.html#state-information

1 files changed, 8 insertions, 2 deletions

diff --git a/web/input/doc/index.md b/web/input/doc/index.md
index f273e73..6604594 100644
--- a/web/input/doc/index.md
+++ b/web/input/doc/index.md
@@ -40,13 +40,19 @@ 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"
 [video]: doc/presentation.html "Nagios::Plugin Presentation"
 [module]: http://search.cpan.org/dist/Nagios-Plugin/ "Nagios::Plugin"
 [guidelines]: doc/guidelines.html "Nagios Plugin Development Guidelines"
-[new-threshold]: doc/new-threshold-syntax.html "New Threshold Syntax"
-[check-many]: doc/check-many.html "Check Aggregation Plugin"
+[new-threshold]: doc/new-threshold-syntax.html "Proposal for New Threshold Syntax"
+[check-many]: doc/check-many.html "Proposal for Check Aggregation Plugin"
+[retention-rfc]: doc/state-retention.html "Proposal for State Retention Routines"
+[retention-api]: doc/faq/private-c-api.html#state-information "State Retention API"
 
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