[5.0] Update the dev docs

[dgrammatiko]

Pull Request for Issue # .

Summary of Changes

Supplemental to the removal of the -es5.js files so the docs reflect the new state

Testing Instructions

Actual result BEFORE applying this Pull Request

Expected result AFTER applying this Pull Request

Link to documentations

Please select:

• Documentation link for docs.joomla.org:

• No documentation changes for docs.joomla.org needed

• Pull Request link for manual.joomla.org:

• No documentation changes for manual.joomla.org needed

@HLeithner

[Fedik]

I have tested this item ✅ successfully on 927a639

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[richard67]

I have tested this item ✅ successfully on 927a639

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_{This comment was created with the J!Tracker Application at issues.joomla.org/tracker/joomla-cms/41041.}

[richard67]

RTC

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_{This comment was created with the J!Tracker Application at issues.joomla.org/tracker/joomla-cms/41041.}

[HLeithner]

thanks