feat(camping): add craftable tent and hammock addon

Tent pitches over a 2x3 flat footprint and lets players skip to dawn
without touching their spawn point. Hammock strings between two posts
3-6 blocks apart (straight or diagonal, +/-1 block height) and keeps
hostile mobs at bay while occupied. Both are craftable (wool/sticks and
wool/string) and mounted in all four worlds.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

camping-supplies-addon/camping_supplies_RP/blocks.json

@@ -0,0 +1,5 @@
+{
+  "format_version": [1, 1, 0],
+  "silverlabs:tent_canvas": { "sound": "cloth" },
+  "silverlabs:hammock_cloth": { "sound": "cloth" }
+}