Re-review large scale job handling page

[Pratichhya]

Revisit certain sections on this page: https://documentation.dataspace.copernicus.eu/APIs/openEO/large_scale_processing.html for further updates

[HansVRP]

To read through documentation and make recommendations

[Pratichhya]

Possible changes to this page:

• Rearrange the description of Large-scale processing in openEO in the introductory paragraph
• Rearrange the showcase example and related topic in a separate section.
• Is preparing the tiling grid and job attributes relevant for each large-scale processing?
• Within the Tuning job options section, how can a general user tune the job options?
• Also, the title start map productionstill shows that this is about this specific showcase rather than the MultiBackendJobManager. So maybe rephrase the title. Then, focusing back on the usecase after defining it in general might be easier