Docs: add google ads performance max warning note

[marcosmarxm]

What

Add a warning note sometimes users have performance max campaigns and google will filter out that data.

How

Describe the solution

Recommended reading order

1. x.java
2. y.python

🚨 User Impact 🚨

Are there any breaking changes? What is the end result perceived by the user?

For connector PRs, use this section to explain which type of semantic versioning bump occurs as a result of the changes. Refer to our Semantic Versioning for Connectors guidelines for more information. Breaking changes to connectors must be documented by an Airbyte engineer (PR author, or reviewer for community PRs) by using the Breaking Change Release Playbook.

If there are breaking changes, please merge this PR with the 🚨🚨 emoji so changelog authors can further highlight this if needed.

Pre-merge Actions

Expand the relevant checklist and delete the others.

New Connector

Community member or Airbyter

• Community member? Grant edit access to maintainers (instructions)
• Unit & integration tests added and passing. Community members, please provide proof of success locally e.g: screenshot or copy-paste unit, integration, and acceptance test output. To run acceptance tests for a Python connector, follow instructions in the README. For java connectors run ./gradlew :airbyte-integrations:connectors:<name>:integrationTest.
• Connector version is set to 0.0.1
  • Dockerfile has version 0.0.1
• Documentation updated
  • Connector's README.md
  • Connector's bootstrap.md. See description and examples
  • docs/integrations/<source or destination>/<name>.md including changelog with an entry for the initial version. See changelog example
  • docs/integrations/README.md

Airbyter

If this is a community PR, the Airbyte engineer reviewing this PR is responsible for the below items.

• Create a non-forked branch based on this PR and test the below items on it
• Build is successful
• If new credentials are required for use in CI, add them to GSM. Instructions.

Updating a connector

Community member or Airbyter

• Grant edit access to maintainers (instructions)
• Unit & integration tests added

Airbyter

If this is a community PR, the Airbyte engineer reviewing this PR is responsible for the below items.

• Create a non-forked branch based on this PR and test the below items on it
• Build is successful
• If new credentials are required for use in CI, add them to GSM. Instructions.

Connector Generator

• Issue acceptance criteria met
• PR name follows PR naming conventions
• If adding a new generator, add it to the list of scaffold modules being tested
• The generator test modules (all connectors with -scaffold in their name) have been updated with the latest scaffold by running ./gradlew :airbyte-integrations:connector-templates:generator:testScaffoldTemplates then checking in your changes
• Documentation which references the generator is updated as needed