docs: add local development MCP client configuration to READMEs (#361)

* docs: add local development MCP client configuration to READMEs

Add instructions for configuring MCP clients to use locally-cloned
and modified servers. This allows developers to test local changes
with MCP clients like Claude Desktop or VS Code.

- Top-level README: Added 'Local Development' section after npx config
- All TypeScript examples: Added 'Local Development' subsection with
  bash one-liner that builds and runs the server
- Python examples (qr-server, say-server): Added local path config

* docs: include all servers in local development config

* docs: use bash wrapper for Python server configs to enable tilde expansion

examples/qr-server/README.md

@@ -12,18 +12,14 @@ First, clone the repository:
 git clone https://github.com/modelcontextprotocol/ext-apps.git
 ```
 
-Then add to your MCP client configuration (stdio transport), replacing the path with your clone location:
+Then add to your MCP client configuration (stdio transport), replacing `~/code/ext-apps` with your clone path:
 
 ```json
 {
   "mcpServers": {
     "qr": {
-      "command": "uv",
-      "args": [
-        "run",
-        "/path/to/ext-apps/examples/qr-server/server.py",
-        "--stdio"
-      ]
+      "command": "bash",
+      "args": ["-c", "uv run ~/code/ext-apps/examples/qr-server/server.py --stdio"]
     }
   }
 }