Update README.md

Author: MelissaGraham

README.md

@@ -9,12 +9,14 @@ These notebooks have drawn from these repositories:
 
 | Title  | Description  |
 |---|---|
-| 01. Intro to DP0 Notebooks | How to use a python notebook, query a DC2 catalog, and retrieve a DC2 image. |
-| 02. Intro to TAP | How to discover, query, and retrieve DC2 catalog data with the Table Access Protocol (TAP) service. |
-| 03. Intro to AFW Display | How to display, manipulate, and overlay data onto DC2 images. |
-| 04. Intro to Butler | How to discover, query, and retrieve DC2 images with the Generation 3 Butler. |
-| | How to query the forced source catalog and construct a variable star light curve. |
-| | How to compare DC2 detections in the Object catalog to the Truth-Match table. |
+| 01. Intro to DP0 Notebooks | Use a python notebook, query a DC2 catalog, and retrieve a DC2 image. |
+| 02. Intro to TAP | Discover, query, and retrieve DC2 catalog data with the Table Access Protocol (TAP) service. |
+| 03. Intro to AFW Display | Display, manipulate, and overlay data onto DC2 images. |
+| 04. Intro to Butler | Discover, query, and retrieve DC2 images with the Generation 3 Butler. |
+| | Query the forced source catalog and construct a variable star light curve. |
+| | Compare DC2 detections in the Object catalog to the Truth-Match table. |
+| | Usng the Stack to run source detection, deblending, and measurement tasks; subtract bright sources from an image; convolve image and detect low-surface brightness sources. Something like [this NB by Alex](https://nbviewer.jupyter.org/github/LSSTScienceCollaborations/StackClub/blob/rendered/SourceDetection/LowSurfaceBrightness.nbconvert.ipynb) |
+| | Usng the Stack to investigate the concept of a footprint: the region of an image used for detecting and measuring source properties. Something like [this NB by Imran](https://nbviewer.jupyter.org/github/LSSTScienceCollaborations/StackClub/blob/rendered/SourceDetection/Footprints.nbconvert.ipynb). |
 
 Additional tutorials will be added as the [DP0 Delegates Assemblies](https://dp0-1.lsst.io/dp0-delegate-resources/index.html) series progresses.