Add comprehensive documentation with i18n support (EN/BG)

- Add docs/ folder with English (en/) and Bulgarian (bg/) documentation
- Create index.md with language switching and links
- English docs: installation, quickstart, architecture, baraql, storage,
  schema, lsm, btree, vector, graph, fts, columnar, transactions,
  distributed, protocol, udf, api-binary, api-http, api-websocket
- Bulgarian docs: installation, quickstart, architecture, baraql,
  schema, lsm, btree, vector, graph, fts, transactions, distributed
- Update README license to BSD 3-Clause
- Add LICENSE file with BSD 3-Clause text

docs/en/api-binary.md

@@ -0,0 +1,74 @@
+# Binary Protocol API
+
+Low-level wire protocol for high-performance client connections.
+
+## Message Format
+
+All messages use big-endian byte order:
+
+```
+┌────────┬────────┬────────┬────────┬─────────────┐
+│ Length │  Type  │  Seq   │ Status │   Payload   │
+│ 4 bytes│ 1 byte │ 2 bytes│ 1 byte │  N bytes    │
+└────────┴────────┴────────┴────────┴─────────────┘
+```
+
+## Message Types
+
+### Query (0x01)
+
+```nim
+let msg = makeQueryMessage(seq, "SELECT * FROM users")
+```
+
+### Insert (0x02)
+
+```nim
+let msg = makeInsertMessage(seq, "users", data)
+```
+
+### Update (0x03)
+
+```nim
+let msg = makeUpdateMessage(seq, "users", updates, where)
+```
+
+### Delete (0x04)
+
+```nim
+let msg = makeDeleteMessage(seq, "users", where)
+```
+
+### Ready (0x05)
+
+```nim
+let msg = makeReadyMessage(seq)
+```
+
+### Error (0x06)
+
+```nim
+let msg = makeErrorMessage(seq, code, message)
+```
+
+## Response Codes
+
+| Code | Name | Description |
+|------|------|-------------|
+| 0x00 | OK | Success |
+| 0x01 | ERROR | General error |
+| 0x02 | AUTH_REQUIRED | Authentication needed |
+| 0x03 | INVALID_QUERY | Query syntax error |
+| 0x04 | NOT_FOUND | Resource not found |
+
+## Serialization
+
+```nim
+import barabadb/protocol/wire
+
+# Serialize value
+let bytes = serializeValue(Value(kind: vkString, strVal: "test"))
+
+# Deserialize value
+let value = deserializeValue(bytes)
+```