SpaceTrooper utilities vignette, README fixing

Author: BenedettaBanzi

.gitignore

@@ -6,3 +6,4 @@
 *.Rproj
 .Rproj.user
 Rplots.pdf
+desktop.ini

README.md

@@ -147,6 +147,7 @@ The package includes three vignettes that cover:
 
 - [Imaging-based spatial transcriptomics workflows](https://bioconductor.org/packages/devel/bioc/vignettes/SpaceTrooper/inst/doc/RNA_tutorial_vignette.html)
 - [CosMx protein workflow](https://bioconductor.org/packages/devel/bioc/vignettes/SpaceTrooper/inst/doc/Protein_tutorial_vignette.html)
+- [SpaceTrooper utilities](https://bioconductor.org/packages/devel/bioc/vignettes/SpaceTrooper/inst/doc/SpaceTrooper_utilities.html)
 - [SpaceTrooper interoperability](https://bioconductor.org/packages/devel/bioc/vignettes/SpaceTrooper/inst/doc/interoperability.html)