Add debugging help

[zklaus]

Description

This is some guidance on how to debug common problems. This was first written in the wiki and is hereby being transferred to the normal documentation.

• Closes #issue_number
• Link to documentation:

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Before you get started

• ☝ Create an issue to discuss what you are going to do

Checklist

It is the responsibility of the author to make sure the pull request is ready to review. The icons indicate whether the item will be subject to the 🛠 Technical or 🧪 Scientific review.

• 🛠 This pull request has a descriptive title
• 🛠 Code is written according to the code quality guidelines
• 🛠 Documentation is available
• 🛠 Tests run successfully
• 🛠 The list of authors is up to date
• 🛠 Any changed dependencies have been added or removed correctly
• 🛠 All checks below this pull request were successful

New or updated recipe/diagnostic

• 🧪 Recipe runs successfully
• 🧪 Recipe is well documented
• 🧪 Figure(s) and data look as expected from literature
• 🛠 Provenance information has been added

New or updated data reformatting script

• 🛠 Documentation is available
• 🛠 The dataset has been added to the CMOR check recipe
• 🧪 Numbers and units of the data look physically meaningful

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[valeriupredoi]

I loves it 😻 Pinging @rswamina and @SarahAlidoost if they want to include (maybe there are already?) such easter eggs in the Tutorial? PS - approved it, even if you want to add more, I reckon that'll do for now?

[SarahAlidoost]

I loves it heart_eyes_cat Pinging @rswamina and @SarahAlidoost if they want to include (maybe there are already?) such easter eggs in the Tutorial? PS - approved it, even if you want to add more, I reckon that'll do for now?

Thanks for tagging me. @zklaus great addition. There is a "Debugging" lesson in the Tutorial. I am not sure if the lesson is still up to date, but when this PR is merged, we should refer to the FAQ page in the lesson. I made an issue ESMValGroup/ESMValTool_Tutorial#233