fix: minor typos for simple-genai-server endpoints and readme

[indexjoseph]

What type of PR is this?
/kind documentation

What this PR does / Why we need it:
Fixes typo within simple-genai-server examples

Which issue(s) this PR fixes:

Closes #

Special notes for your reviewer:

[agones-bot]

Build Succeeded 👏

Build Id: 1c8426a8-542e-4009-bef3-ece7f160592c

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

• image: us-docker.pkg.dev/agones-images/ci/agones-controller:1.39.0-dev-0e22a5c-amd64
• image: us-docker.pkg.dev/agones-images/ci/agones-extensions:1.39.0-dev-0e22a5c-amd64
• image: us-docker.pkg.dev/agones-images/ci/agones-sdk:1.39.0-dev-0e22a5c-linux-amd64
• image: us-docker.pkg.dev/agones-images/ci/agones-ping:1.39.0-dev-0e22a5c-amd64
• image: us-docker.pkg.dev/agones-images/ci/agones-allocator:1.39.0-dev-0e22a5c-amd64
• Linux C++ SDK (build): agonessdk-1.39.0-dev-0e22a5c-amd64-linux-arch_64.tar.gz
• SDK Server: agonessdk-server-1.39.0-dev-0e22a5c-amd64.zip

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

• https://0e22a5c-dot-preview-dot-agones-images.appspot.com/

To install this version:

• git fetch https://github.com/googleforgames/agones.git pull/3673/head:pr_3673 && git checkout pr_3673
• helm install agones ./install/helm/agones --namespace agones-system --set agones.image.registry=us-docker.pkg.dev/agones-images/ci --set agones.image.tag=1.39.0-dev-0e22a5c-amd64

[igooch]

LGTM