feat(emacs): Tecosaur LaTeX preview

modules/home/users/crumb/emacs.nix

@@ -23,7 +23,7 @@ in {
       };
 
       emacsDataDir = "${config.xdg.dataHome}/emacs";
-      emacsCacheDir = "${emacsDataDir}/cache";
+      emacsCacheDir = "${config.xdg.cacheHome}/emacs";
       straightBaseDir = "${emacsDataDir}/straight";
 
       fontPackages = [
@@ -47,7 +47,11 @@ in {
           capt-of
           pgf # Includes TikZ.
           tikz-cd # Commutative diagrams w/ TikZ.
+          quiver # Commutative diagrams w/ TikZ & q.uiver.app.
           metafont
+          preview # For new-gen org-latex-preview.
+          mylatexformat # For new-gen org-latex-preview.
+          collection-fontsrecommended # Essential fonts.
           ;
       };