Initial LegendOfZeldaALinkToThePastSNESRecomp scaffold

mods/preloaded/README.md

@@ -0,0 +1,22 @@
+# Preloaded mods
+
+Ship reviewed, default-disabled packages here:
+
+```text
+packages/<package-id>/<version>/
+  manifest.toml
+  ...
+```
+
+A manifest's `[[target]]` names this title as `game_id = "legendofzeldaalinktothepast-usa"` with the
+ROM's SHA-256 (both live in `rom_identity.txt`). CMakeLists.txt declares this
+directory with `snesrecomp_target_mod_catalog` and the FRAMEWORK stages
+`packages/` beside the executable on every build -- do not add a copy step of
+your own, and do not spell the destination: it belongs to snesrecomp, so a
+future change to the layout touches one file instead of every port. Nothing
+placed beside the executable by hand survives a build.
+Players install `.snesmod` archives through the launcher's Mods page, which
+the runtime keeps under its own state beside the executable.
+
+See `snesrecomp/docs/MOD_PACKAGES.md` for the manifest format and the
+trusted-plugin registration a package can activate.