0.15 migration: Fix name of subpixel feature that was removed (#1895)

release-content/0.15/migration-guides/10193_Cosmic_text.md

@@ -1,5 +1,5 @@
 - `Text2dBounds` has been replaced with `TextBounds`, and it now accepts `Option`s to the bounds, instead of using `f32::INFINITY` to indicate lack of bounds
 - Textsizes should be changed, dividing the current size with 1.2 will result in the same size as before.
 - `TextSettings` struct is removed
-- Feature `subpixel_alignment` has been removed since cosmic-text already does this automatically
+- Feature `subpixel_glyph_atlas` has been removed since cosmic-text already does this automatically
 - TextBundles and things rendering texts requires the `CosmicBuffer` Component on them as well