Update _index.md

#44 
@njr2128 
I corrected the link to what I think this must be:  /documents/pdf/2023_dyes-pigments_samples.pdf by Naomi Rosenkranz and Megan Lennon (2023-02-28)

content/resources/student-projects/_index.md

@@ -69,7 +69,7 @@ Their exploratory and experimental projects serve as companion pieces to *Secret
 
 -  [Dyeing with Onion Skins](/resources/student-projects/su22_fld_cunningham_annika_onion-skin-dyeing/) by Annika Cunningham (2022-07-18)
 -  [Making Pigment from Madder: a Trio of Recipes](/resources/activity-sheets/sp22_fld_rosenkranz_naomi_madder-lake-trio/) by Naomi Rosenkranz (2022-07-19)
--  [Materials Used for Making Renaissance Dyes and Pigments](/resources/student-projects/materials/) by Naomi Rosenkranz and Megan Lennon (2023-02-28)
+-  [Materials Used for Making Renaissance Dyes and Pigments](/documents/pdf/2023_dyes-pigments_samples.pdf) by Naomi Rosenkranz and Megan Lennon (2023-02-28)
 
 ![azurite shells](/images/azurite-shells.jpg)
 
@@ -86,4 +86,4 @@ The Spring 2019 course _Transforming Texts: Textual Analysis, Literary Modeling,
 -   [Chromatic Index](/documents/pdf/SP19_Soto_Chromatic-Index.pdf) by Guillermo Soto, Clement Godbarge, and Yuhe Zheng. See also [PDF of PowerPoint presentation](/documents/pdf/SP19_Chromatic-Index-Presentation.pdf)
 -   [Augmented Reality Group (ARGroup)](/documents/pdf/SP19_ARGroup.pdf) by Mahzabin Hasnath, Kathleen Lee, and Taewan Shim. See also PowerPoint presentation [[PDF](/documents/pdf/SP19_ARGroup-Presentation.pdf)] [[PPTX](/documents/student-projects/SP19_ARGroup-Presentation.pptx)]
 
-![2018 Paleography](/images/2018_paleography_toulouse_for-webpages.jpg)
+![2018 Paleography](/images/2018_paleography_toulouse_for-webpages.jpg)