Remove all HKD/satshkd support, add all EU languages

- Removed all references to HKD and satshkd from codebase
- Updated README, package.json, documentation to focus on EUR/sats
- Removed HKD-specific files (convert_btcticker.js, archive/hkd_historical)
- Updated all titles from SatsHKD/HKDSAT to SatsEUR/EURSAT
- Removed HKD image reference from sats.hbs
- Updated Python scripts to use 'historical' instead of 'hkd_historical'
- Added all 16 missing EU official languages with translations:
  * Bulgarian (bg), Croatian (hr), Czech (cs), Danish (da)
  * Estonian (et), Finnish (fi), Greek (el), Hungarian (hu)
  * Irish (ga), Latvian (lv), Lithuanian (lt), Maltese (mt)
  * Romanian (ro), Slovak (sk), Slovenian (sl), Swedish (sv)
- Now supports all 24 EU official languages

package.json

@@ -1,7 +1,7 @@
 {
-    "name": "satshkd-vercel",
+    "name": "eursats-vercel",
     "version": "1.0.0",
-    "description": "Deploy express js to vercel.",
+    "description": "EUR/Sats historical chart - Deploy express js to vercel.",
     "main": "index.js",
     "scripts": {
         "start": "node index.js"