fix: correct typo in llm service vscode command

@ W-17466904@

Author: peternhale

src/index.ts

@@ -11,4 +11,4 @@ export * from './types';
 export const telemetryCommand = 'sf.vscode.core.get.telemetry';
 export const loggerCommand = 'sf.vscode.core.logger.get.instance';
 export const llmServiceCommand =
-  'salesforcedx-einstein-gpt.getLlmServiceInstance';
+  'salesforcedx-einstein-gpt.getLLMServiceInstance';