docs: change old documentation links of packages in README files

[ashwinair]

Description

Changes old firebase.flutter.dev/docs links to new firebase.google.com/docs
of these packages:

• cloud_firestore
• cloud_firestore_web
• cloud_functions
• cloud_functions_web
• firebase_analytics
• fiebase_app_check_web
• firebase_app_installations_web
• firebase_app_installations
• firebase_core
• firebase_database
• firebase_database_web
• firebase_dynamic_links
• firebase_in_app_messaging
• firebase_messaging
• firebase_messaging_web
• firebase_ml_model_downloader
• firebase_performance
• firebase_remote_config_web
• firebase_storage
• firebase_storage_web

Related Issues

closes #11995

Checklist

Before you create this PR confirm that it meets all requirements listed below by checking the relevant checkboxes ([x]).
This will ensure a smooth and quick review process. Updating the pubspec.yaml and changelogs is not required.

• I read the Contributor Guide and followed the process outlined there for submitting PRs.
• My PR includes unit or integration tests for all changed/updated/fixed behaviors (See Contributor Guide).
• All existing and new tests are passing.
• I updated/added relevant documentation (doc comments with ///).
• The analyzer (melos run analyze) does not report any problems on my PR.
• I read and followed the Flutter Style Guide.
• I signed the CLA.
• I am willing to follow-up on review comments in a timely manner.

Breaking Change

Does your PR require plugin users to manually update their apps to accommodate your change?

• Yes, this is a breaking change.
• No, this is not a breaking change.

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[russellwheatley]

Hey, thanks for the PR! I've made some more suggestions to remove links to deprecated website.

[ashwinair]

Hi @russellwheatley :)

I removed the lines as you suggested. can you have a look and tell me if there is anything else I have to edit.

[russellwheatley]

Sorry, @ashwinair, a PR has been merged that conflicts with this file packages/cloud_firestore_odm/cloud_firestore_odm_generator/README.md, do you mind resolving the conflict, please? Thanks 🙏

[ashwinair]

do you mind resolving the conflict, please?

@russellwheatley, resolved.