add changeset (#4)

.changeset/spicy-crabs-draw.md

@@ -0,0 +1,12 @@
+---
+"app-builder-lib": minor
+---
+
+Default to LZO compression for snap packages.
+This greatly improves cold startup performance (https://snapcraft.io/blog/why-lzo-was-chosen-as-the-new-compression-method).
+LZO has already been adopted by most desktop-oriented snaps outside of the Electron realm.
+
+For the rare case where developers prefer a smaller file size (XZ) to vastly improved decompression performance (LZO),
+provide an option to override the default compression method.
+
+Consumers do not need to update their configuration unless they specifically want to stick to XZ compression.