Update community template docs to clarify steps for Cloud users

Docs for creating community templates are not clear that Cloud users must install the InfluxDB OSS version to access the CLI.

##### Relevant URLs
- https://docs.influxdata.com/influxdb/v2.0/influxdb-templates/create/
- https://docs.influxdata.com/influxdb/v2.0/get-started/

##### What products and version are you using?
Any cloud user

Please update the following URL:
- https://docs.influxdata.com/influxdb/v2.0/influxdb-templates/create/
For step 1, change `Install InfluxDB` to something like the following:

For OSS Users, run InfluxDB (link to https://docs.influxdata.com/influxdb/v2.0/get-started/, create an anchor at Run InfluxDB section)
For Cloud Users, download and install InfluxDB OSS. (link to top of https://docs.influxdata.com/influxdb/v2.0/get-started/)

Update https://docs.influxdata.com/influxdb/v2.0/get-started/, provide an anchor at the Run InfluxDB section.