chore: add LICENSE, README, VERSION, .editorconfig, expand .gitignore

Add project housekeeping files and sync manifest version to 0.1.0.
Also stages previously untracked chat summaries and score-ratio docs.

Co-authored-by: Cursor <cursoragent@cursor.com>

manifest.json

@@ -1,7 +1,7 @@
 {
   "manifest_version": 2,
   "name": "Reddit Tweaks",
-  "version": "1.0.0",
+  "version": "0.1.0",
   "description": "Reskins old Reddit post listings with badge-style subreddit and comment indicators.",
   "permissions": ["storage", "activeTab"],
   "icons": {