docs: add reset_from_parent

Author: philip

content/docs/shared-content/mcp-tools.md

@@ -21,6 +21,7 @@ The Neon MCP Server provides the following actions, which are exposed as "tools"
 - `delete_branch`: Deletes an existing branch from a Neon project.
 - `describe_branch`: Retrieves details about a specific branch, such as its name, ID, and parent branch.
 - `list_branch_computes`: Lists compute endpoints for a project or specific branch, including compute ID, type, size, and autoscaling information.
+- `reset_from_parent`: Resets the current branch to its parent's state, discarding local changes. Automatically preserves to backup if branch has children, or optionally on request.
 
 **SQL query execution:**