"Common Pitfalls" in docs

### Documentation Is:

- [X] Missing or needed?
- [ ] Confusing
- [ ] Not sure?

### Please Explain in Detail...

In this [Slack conversation](https://chartjs.slack.com/archives/C0N98KP1N/p1659528683123159?thread_ts=1659520704.993059&cid=C0N98KP1N) with @LeeLenaleee, it was revealed that there's a substantial volume of repeated questions or support issues, often addressed similarly (e.g., by providing a link to [3.x Migration Guide](https://www.chartjs.org/docs/latest/getting-started/v3-migration.html)).

### Your Proposal for Changes

We can add a new section to the docs, linked from the sidebar, that would provide concise pieces of guidance.

"Known Issues" is probably not the best name since it "feels like it shows known issues in the code instead of user migration errors". So, "Common Pitfalls" might be a better name.

We can use this issue to collect cases.

### Example

_No response_