feat: add dialect and configuration instructions (#79)

Author: averikitsch

README.md

@@ -44,7 +44,26 @@ gemini extensions install https://github.com/gemini-cli-extensions/spanner
 
 ### Configuration
 
-Set the following environment variables before starting the Gemini CLI. These variables can be loaded from a `.env` file.
+You will be prompted to configure the following settings during installation. These settings are saved in an `.env` file within the extension's directory.
+
+*   `SPANNER_PROJECT`: The GCP project ID.
+*   `SPANNER_INSTANCE`: The Spanner instance ID.
+*   `SPANNER_DATABASE`: The Spanner database ID.
+*   `SPANNER_DIALECT`: (Optional) The SQL dialect of the Spanner database: 'googlesql' or 'postgresql'. Defaults to "googlesql".
+
+To view or update your configuration:
+
+**List Settings:**
+*   Terminal: `gemini extensions list`
+*   Gemini CLI: `/extensions list`
+
+**Update Settings:**
+*   Terminal: `gemini extensions config spanner [setting name] [--scope <scope>]`
+    *   `setting name`: (Optional) The single setting to configure.
+    *   `scope`: (Optional) The scope of the setting in (`user` or `workspace`). Defaults to `user`.
+*   Currently, you must restart the Gemini CLI for changes to take effect. We recommend using `gemini --resume` to resume your session.
+
+Alternatively, you can manually set these environment variables before starting the Gemini CLI:
 
 ```bash
 export SPANNER_PROJECT="<your-gcp-project-id>"
@@ -53,7 +72,9 @@ export SPANNER_DATABASE="<your-spanner-database-id>"
 export SPANNER_DIALECT="googlesql" # Optional: "googlesql" or "postgresql". Defaults to "googlesql".
 ```
 
-Ensure [Application Default Credentials](https://cloud.google.com/docs/authentication/gcloud) are available in your environment.
+> [!NOTE]
+> * Ensure [Application Default Credentials](https://cloud.google.com/docs/authentication/gcloud) are available in your environment.
+> * See [Troubleshooting](#troubleshooting) for debugging your configuration.
 
 ### Start Gemini CLI
 

gemini-extension.json

@@ -20,14 +20,19 @@
       "envVar": "SPANNER_PROJECT"
     },
     {
-      "name": "Instance ID",
+      "name": "Instance",
       "description": "ID of the Spanner instance",
       "envVar": "SPANNER_INSTANCE"
     },
     {
-      "name": "Database ID",
+      "name": "Database",
       "description": "ID of the Spanner database",
       "envVar": "SPANNER_DATABASE"
+    },
+    {
+      "name": "Database Dialect",
+      "description": "(Optional) The SQL dialect of the Spanner Database: 'googlesql' or 'postgresql'. (Default: 'googlesql')",
+      "envVar": "SPANNER_DIALECT"
     }
   ]
 }