Workflow: Check if README.md and docs/README.md are in sync

[kuanyi-ng]

📑 Summary

This PR adds a GitHub workflow that checks if README.md and docs/README.md have the same content.

This is part of issue #2456. (Documentation section)

📏 Design Decisions

About workflow's triggers

In the contribution guide, it said that documentation-related changes can be committed directly to the develop branch.
So I made this workflow to target push and pull_request events for both master and develop branches.

Possible improvements (for another PR)

1. Output which README.md is newer so it's easier to sync both README.md files.
   a. still don't have a concrete idea on how to determine if one README.md is newer than the other
   a. this information might be available from git log or git blame
2. Sync the content of README.md and docs/README.md as a part of the workflow.
   a. it might be possible to automatically apply the changes to either one of the READMEs.
3. Also check if CHANGELOG.md and docs/CHANGELOG.md have the same content.

📋 Tasks

Make sure you

• 📖 have read the contribution guidelines
• 💻 have added unit/e2e tests (if appropriate)
• 🔖 targeted develop branch

[ashishjain0512]

Thank you that's super userful!

[mmorel-35]

Why merging this if the new workflow doesn't pass?
Now every PR on the master is going to fail

[kuanyi-ng]

Why merging this if the new workflow doesn't pass? Now every PR on the master is going to fail

@mmorel-35
Sorry for not making sure the workflow will pass before this PR is merged.
Following are a few solutions to this situation:

1. Revert this PR → Sync README.md and re-adding this workflow in one PR
2. Sync README.md in another PR (without reverting this PR)

Assuming that syncing both README.md will take up some time, I think reverting this PR is better for the moment.
What do you think?

[mmorel-35]

I prefer the second option, this feature is great. The synchronisation just need to be fixed

[kuanyi-ng]

I'm afraid I don't know much about mermaid.js to proceed with the second option. (Just found out about mermaid.js last week). Are there any guidelines that I can follow while syncing both README.md?

[Yash-Singh1]

There will be some road bumps when doing this:

1. Ensure if we need the CI checks in the documentation header.
2. Make sure the images for the Mermaid.js diagrams should appear in the README and documentation (README should use different code fence names than documentation)
3. Sync links between README and docs without having any resolving problems as they exist in different in different directories