added simple websocket test

- bump to v0.21.1

cmd/relay-tester/README.md

@@ -0,0 +1,71 @@
+# relay-tester
+
+A command-line tool for testing Nostr relay implementations against the NIP-01 specification and related NIPs.
+
+## Usage
+
+```bash
+relay-tester -url <relay-url> [options]
+```
+
+## Options
+
+- `-url` (required): Relay websocket URL (e.g., `ws://127.0.0.1:3334` or `wss://relay.example.com`)
+- `-test <name>`: Run a specific test by name (default: run all tests)
+- `-json`: Output results in JSON format
+- `-v`: Verbose output (shows additional info for each test)
+- `-list`: List all available tests and exit
+
+## Examples
+
+### Run all tests against a local relay:
+```bash
+relay-tester -url ws://127.0.0.1:3334
+```
+
+### Run all tests with verbose output:
+```bash
+relay-tester -url ws://127.0.0.1:3334 -v
+```
+
+### Run a specific test:
+```bash
+relay-tester -url ws://127.0.0.1:3334 -test "Publishes basic event"
+```
+
+### Output results as JSON:
+```bash
+relay-tester -url ws://127.0.0.1:3334 -json
+```
+
+### List all available tests:
+```bash
+relay-tester -list
+```
+
+## Exit Codes
+
+- `0`: All required tests passed
+- `1`: One or more required tests failed, or an error occurred
+
+## Test Categories
+
+The relay-tester runs tests covering:
+
+- **Basic Event Operations**: Publishing, finding by ID/author/kind/tags
+- **Filtering**: Time ranges, limits, multiple filters, scrape queries
+- **Replaceable Events**: Metadata and contact list replacement
+- **Parameterized Replaceable Events**: Addressable events with `d` tags
+- **Event Deletion**: Deletion events (NIP-09)
+- **Ephemeral Events**: Event handling for ephemeral kinds
+- **EOSE Handling**: End of stored events signaling
+- **Event Validation**: Signature verification, ID hash verification
+- **JSON Compliance**: NIP-01 JSON escape sequences
+
+## Notes
+
+- Tests are run in dependency order (some tests depend on others)
+- Required tests must pass for the relay to be considered compliant
+- Optional tests may fail without affecting overall compliance
+- The tool connects to the relay using WebSocket and runs tests sequentially
+