Fix documentation for multi-cluster allocation

[pooneh-m]

No description provided.

[agones-bot]

Build Succeeded 👏

Build Id: 1df3c681-2084-4cd5-92e2-cfc4990080bb

The following development artifacts have been built, and will exist for the next 30 days:

• image: gcr.io/agones-images/agones-controller:1.3.0-7ea1c9b
• image: gcr.io/agones-images/agones-sdk:1.3.0-7ea1c9b
• image: gcr.io/agones-images/agones-ping:1.3.0-7ea1c9b
• Linux C++ SDK (build): agonessdk-1.3.0-7ea1c9b-linux-arch_64.tar.gz
• SDK Server: agonessdk-server-1.3.0-7ea1c9b.zip

A preview of the website (the last 30 builds are retained):

• https://7ea1c9b-dot-preview-dot-agones-images.appspot.com/

To install this version:

• git fetch https://github.com/GoogleCloudPlatform/agones.git pull/1235/head:pr_1235 && git checkout pr_1235
• helm install ./install/helm/agones --namespace agones-system --name agones --set agones.image.tag=1.3.0-7ea1c9b

[google-oss-robot]

New changes are detected. LGTM label has been removed.

[google-oss-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: markmandel, pooneh-m

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [markmandel,pooneh-m]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[google-oss-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: markmandel, pooneh-m

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [markmandel,pooneh-m]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[agones-bot]

Build Succeeded 👏

Build Id: fc42116b-10cd-4a9f-9faa-5251f6f376b1

The following development artifacts have been built, and will exist for the next 30 days:

• image: gcr.io/agones-images/agones-controller:1.3.0-4b9f588
• image: gcr.io/agones-images/agones-sdk:1.3.0-4b9f588
• image: gcr.io/agones-images/agones-ping:1.3.0-4b9f588
• Linux C++ SDK (build): agonessdk-1.3.0-4b9f588-linux-arch_64.tar.gz
• SDK Server: agonessdk-server-1.3.0-4b9f588.zip

A preview of the website (the last 30 builds are retained):

• https://4b9f588-dot-preview-dot-agones-images.appspot.com/

To install this version:

• git fetch https://github.com/GoogleCloudPlatform/agones.git pull/1235/head:pr_1235 && git checkout pr_1235
• helm install ./install/helm/agones --namespace agones-system --name agones --set agones.image.tag=1.3.0-4b9f588