refactor: group stow packages into common, mac and kde

Split the packages by platform so each app stays an opt-in Stow package
under common/, mac/ or kde/. KDE gets its own Fastfetch, Helium and
Spectacle packages, and darwin-breeze becomes kde/theme. The READMEs
document stowing a whole group as well as individual packages.

common/micro/.config/micro/.gitignore

@@ -0,0 +1,2 @@
+backups/
+buffers/

common/micro/.config/micro/bindings.json

@@ -0,0 +1,4 @@
+{
+    "Alt-/": "lua:comment.comment",
+    "CtrlUnderscore": "lua:comment.comment"
+}

common/micro/.config/micro/settings.json

@@ -0,0 +1,3 @@
+{
+    "mkparents": true
+}