Merge release/2.1 to master (#533)

* Forward FlowDirection from TeachingTip to content (#515)

* Add script to automate repacking the nupkg with store signed appx files (#520)

* dont try to activate recycle pool which is not public. (#526)

* dont try to activate recycle pool which is not public.

* empty commit to kick the pipeline

* Ensure properties before they are used.

* Fix crash in uniform grid when fed an empty list (#529)

* Add updated intellisense file for 2.1 (#521)