Document create org feature

**ETA:** Early December 2022

InfluxDB Cloud will allow paid users to create new organizations, which are a way to isolate data and resources. Organizations can be useful for enabling a group of users to operate multiple environments (dev, staging, prod), different teams, and different providers/regions in the same InfluxDB Cloud account.

InfluxDB OSS supports multiple organizations as well. However, there is a different design and implementation for multiple organizations in InfluxDB Cloud. Multiple organizations will only be available to paid accounts. There is also additional functionality to select a different provider/region for the organization.

##### Relevant URLs
We'll need to add "Create organization" and "Switch organization" pages to the "Manage organizations" section.

- https://docs.influxdata.com/influxdb/cloud/organizations/

Start with the linked InfluxDB Cloud organizations documentation and its “Manage organizations” section. Add the requested “Create organization” and “Switch organization” pages, covering the Cloud behavior described in the issue; the work is done when both pages are available in that section.

Written by the indexing model from the issue text.