docs: Add invalidate/reconsiderblock JSON-RPC API.

This adds documentation for the new invalidateblock and reconsiderblock
RPC commands to the JSON-RPC API docs.

docs/json_rpc_api.mediawiki

@@ -342,6 +342,10 @@ the method name for further details such as parameter and return information.
 |Y
 |Returns a list of all commands or help for a specified command.
 |-
+|[[#invalidateblock|invalidateblock]]
+|N
+|Permanently invalidates a block as if it had violated consensus rules.
+|-
 |[[#livetickets|livetickets]]
 |Y
 |Returns live ticket hashes from the ticket database.
@@ -358,6 +362,10 @@ the method name for further details such as parameter and return information.
 |N
 |Queues a ping to be sent to each connected peer.
 |-
+|[[#reconsiderblock|reconsiderblock]]
+|N
+|Reconsiders a block for validation and best chain selection by removing any invalid status from it and its ancestors.  Any descendants that are neither themselves marked as having failed validation, nor descendants of another such block, are also made eligibile for best chain selection.
+|-
 |[[#regentemplate|regentemplate]]
 |Y
 |Asks the daemon to regenerate the mining block template.
@@ -2161,6 +2169,26 @@ of the best block.
 
 ----
 
+====invalidateblock====
+{|
+!Method
+|invalidateblock
+|-
+!Parameters
+|
+# <code>block hash</code>: <code>(string, required)</code> the hash of the block to invalidate
+|-
+!Description
+|
+: Permanently invalidates a block as if it had violated consensus rules.
+: Use [[#reconsiderblock|reconsiderblock]] to remove the invalid status.
+|-
+!Returns
+|Nothing
+|}
+
+----
+
 ====livetickets====
 {|
 !Method
@@ -2243,6 +2271,26 @@ of the best block.
 
 ----
 
+====reconsiderblock====
+{|
+!Method
+|reconsiderblock
+|-
+!Parameters
+|
+# <code>block hash</code>: <code>(string, required)</code> the hash of the block to reconsider
+|-
+!Description
+|
+: Reconsiders a block for validation and best chain selection by removing any invalid status from it and its ancestors.
+: Any descendants that are neither themselves marked as having failed validation, nor descendants of another such block, are also made eligibile for best chain selection.
+|-
+!Returns
+|Nothing
+|}
+
+----
+
 ====regentemplate====
 {|
 !Method