Add check tool for plugin config (#24)

README.md

@@ -6,6 +6,12 @@
 $ solana-validator --geyser-plugin-config ./config.json
 ```
 
+### Plugin config check
+
+```
+cargo-fmt && cargo run --bin config-check -- --config config.json
+```
+
 ### Client
 
 - Always broadcast new slots

src/bin/config-check.rs

@@ -0,0 +1,16 @@
+use {clap::Parser, solana_geyser_grpc::config::Config};
+
+#[derive(Debug, Parser)]
+#[clap(author, version, about)]
+struct Args {
+    #[clap(short, long, default_value_t = String::from("config.json"))]
+    /// Path to config
+    config: String,
+}
+
+fn main() -> anyhow::Result<()> {
+    let args = Args::parse();
+    let _config = Config::load_from_file(args.config)?;
+    println!("Config is OK!");
+    Ok(())
+}