EAI - Documentation: Project structure

**Describe the solution you'd like**
The file structure and important files of the eai-template should be documented and described.
A table-based documentation which short information about the purpose of folders and files must be created.

**Describe alternatives you've considered**
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**Additional context**
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Start by reviewing the eai-template file structure and identifying its folders and important files. Create table-based documentation with brief purpose descriptions for each, then verify that the resulting overview covers the project structure.

Written by the indexing model from the issue text.