updates about Gemini CLI Extension usage

USAGE.md

@@ -12,6 +12,8 @@ export VIKUNJA_USERNAME="<your_vikunja_username>"
 export VIKUNJA_PASSWORD="<your_vikunja_password>"
 ```
 
+# MCP
+
 ## Adding the MCP Server
 
 To add the Vikunja MCP server to the Gemini CLI, use the following command:
@@ -43,3 +45,66 @@ To remove the Vikunja MCP server from the Gemini CLI, use the following command:
 ```bash
 gemini mcp remove vikunja
 ```
+
+# Gemini CLI Extension
+
+We now can run this with the Gemini CLI extension method which is far far easier to install.
+
+Just use the following invokation:
+```
+$ gemini extensions install https://forgejo.freshbrewed.science/builderadmin/vikunjamcp
+```
+
+This should install the CLI and activate it:
+```
+$ gemini extensions install https://forgejo.freshbrewed.science/builderadmin/vikunjamcp
+Installing extension "vikunja".
+**Extensions may introduce unexpected behavior. Ensure you have investigated the extension source and trust the author.**
+This extension will run the following MCP servers:
+  * nodeServer (local): docker run -i --rm -e VIKUNJA_URL -e VIKUNJA_USERNAME -e VIKUNJA_PASSWORD harbor.freshbrewed.science/library/vikunjamcp:0.11
+Do you want to continue? [Y/n]: Y
+Extension "vikunja" installed successfully and enabled.
+builder@DESKTOP-QADGF36:~/Workspaces/vikunjamcp$ gemini extensions list
+✓ vikunja (1.0.11)
+ Path: /home/builder/.gemini/extensions/vikunja
+ Source: https://forgejo.freshbrewed.science/builderadmin/vikunjamcp (Type: git)
+ Enabled (User): true
+ Enabled (Workspace): true
+ MCP servers:
+  nodeServer
+```
+
+Because this does not hardcode a server, user or password, you'll want to set that before invoking Gemini, e.g.
+```
+$ export VIKUNJA_URL='https://vikunja.steeped.space'
+$ export VIKUNJA_USERNAME='idjohnson'
+$ export VIKUNJA_PASSWORD='xxxxxxxxxxxxxxxxxxxxxxx'
+$ gemini
+```
+
+Personally, I now set those in my `~/.bashrc` (or zshrc if you use zshell).
+
+When launched, this will launch it in Docker and you can use ctrl-t to see the tools
+
+```
+🟢 nodeServer (from vikunja) - Ready (5 tools)
+  Tools:
+  - add_task
+    Adds a new task to a Vikunja project.
+
+    :param project_id: The ID of the project to add the task to.
+    :param title: The title of the new task.
+    :param description: An optional description for the task.
+  - close_task
+    Closes (marks as done) a task in Vikunja.
+
+    :param task_id: The ID of the task to close.
+  - login
+    Authenticates with the Vikunja API to get a session token.
+  - lookup_project
+    Retrieves all projects the user has access to and lists them by name and ID.
+  - search_tasks
+    Searches for tasks in Vikunja.
+
+    :param query: The search string to use for finding tasks.
+```