feat(imageLoader):Add an nth image loader strategy (#10) (#3044)

* feat(imageLoader):Add an nth image loader strategy (#10)

* Updates for PR for nth menu

* performance:Prior implementation was O(n^2), taking about 50 ms

* feat:Nth image loader, added docs as requested

platform/docs/docs/deployment/index.md

@@ -97,12 +97,12 @@ support it yet, but it is gaining wider adoption.
 If you have an existing archive and intend to host the OHIF Viewer at the same
 domain name as your archive, then connecting the two is as simple as following
 the steps layed out in our
-[Configuration Essentials Guide](./../configuration/index.md).
+[Configuration Essentials Guide](./../configuration/configurationFiles.md).
 
 #### What if I don't have an imaging archive?
 
 We provide some guidance on configuring a local image archive in our
-[Data Source Essentials](./../configuration/index.md#set-up-a-local-DICOM-server)
+[Data Source Essentials](./../configuration/dataSources/introduction.md)
 guide. Hosting an archive remotely is a little trickier. You can check out some
 of our [advanced recipes](#recipes) for modeled setups that may work for you.
 

platform/docs/docs/platform/extensions/modules/hpModule.md

@@ -219,6 +219,17 @@ matching), or provides and array of ids which will
 make the ProtocolEngine to choose the best matching protocol (based on
 protocolMatching rules, which is next section).
 
+### imageLoadStrategy
+The image load strategy specifies a function (by name) containing logic to re-order
+the image load requests.  This allows loading images viewed earlier to be done
+sooner than those loaded later.  The available strategies are:
+
+* interleaveTopToBottom to start at the top and work towards the bottom, for all series being loaded
+* interleaveCenter is like top to bottom but starts at the center
+* nth is a strategy that loads every nth instance, starting with the center
+and end points, and then filling in progressively all along the image.  This results in partial
+image view very quickly.
+
 ### protocolMatchingRules
 A list of criteria for the protocol along with the provided points for ranking.