[ISSUE-4474] Replace default database guide

[leandroBorgesFerreira]

🎯 Goal

Documentation for database replacement.

☑️Contributor Checklist

General

• I have signed the Stream CLA (required)
• Assigned a person / code owner group (required)
• Thread with the PR link started in a respective Slack channel (#android-chat-core or #android-chat-ui) (required)
• PR targets the develop branch
• PR is linked to the GitHub issue it resolves

Code & documentation

• [ ] Changelog is updated with client-facing changes
• [ ] New code is covered by unit tests
• [ ] Comparison screenshots added for visual changes
• Affected documentation updated (KDocs, docusaurus, tutorial)

☑️Reviewer Checklist

• UI Components sample runs & works
• Compose sample runs & works
• UI Changes correct (before & after images)
• Bugs validated (bugfixes)
• New feature tested and works
• Release notes and docs clearly describe changes
• All code we touched has new or updated KDocs

🎉 GIF

Please provide a suitable gif that describes your work on this pull request

[kanat]

@JcMinarro, @DanielNovak, @liviu-timar,

Can we close this one?
Seems to be quite outdated.