Add to changelog for 1.3

Author: cderv

news/changelog-1.3.md

@@ -37,6 +37,7 @@
 - Add support for automatically converting SVG images to PDF ([#2575](https://github.com/quarto-dev/quarto-cli/issues/2575))
 - Previously, if the `pdf-engine` was set to `latexmk`, we would bypass many features of Quarto and use Pandoc to produce the PDF output. Starting in in Quarto 1.3, all Quarto features will be enabled for the `latexmk` engine and `latexmk` will be used to run the PDF generation loop.
 - Fix author processing in default PDFs for complex author names (#3483)
+- Remove excessive vertical space between theorem type blocks ([#3776](https://github.com/quarto-dev/quarto-cli/issues/3776)).
 
 ## Beamer Format