docs: trim README — drop Development section, clarify license line

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: CodingMasterLSW

README.md

@@ -91,15 +91,6 @@ args = ["-y", "english-tutor-mcp"]
 
 Relocate everything with `ENGLISH_TUTOR_DB=/path/to/db.sqlite`. Delete the directory to erase all data — nothing leaves your machine.
 
-## Development
-
-```bash
-npm install
-npm test        # tsc build + unit tests + protocol-level E2E over real stdio
-```
-
-Layout: `src/core` (domain logic, transport-agnostic) · `src/db` (SQLite schema) · `src/mcp` (tool/prompt handlers — validation and delegation only) · `src/taxonomy.ts` (the analysis lens) · `src/prompts.ts` (slash-command bodies).
-
 ## License
 
-MIT
+MIT License