#1708: newdoku contributing setup

[ymohandi]

This PR fixes #1708

New doku contributing setup

Implemented changes:

Add a step-by-step setup guide for new developers to install and configure IDEasy.

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Checklist for this PR

Make sure everything is checked before merging this PR. For further info please also see
our DoD.

• When running mvn clean test locally all tests pass and build is successful
• PR title is of the form #«issue-id»: «brief summary» (e.g. #921: fixed setup.bat). If no issue ID exists, title only.
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  with internal

[CLAassistant]

All committers have signed the CLA.

[coveralls]

Pull Request Test Coverage Report for Build 22574027438

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

• For more information on this, see Tracking coverage changes with pull request builds.
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• For a quick fix, rebase this PR at GitHub. Your next report should be accurate.

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 70.474%

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Totals
Change from base Build 22187698026:	0.0%
Covered Lines:	10493
Relevant Lines:	14305

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💛 - Coveralls

[hohwille]

@ymohandi thanks for your first PR. Great job - you already mastered AsciiDoc and have produced a very good and clear guide for the initial setup. 👍
I left some comments for improvement - mainly as constructive comments. When you go to Files changed tab you can select all of them together as batch and commit in one click if you accept my suggestions what automatically resolves these review threads.

[hohwille]

@ymohandi you also need to sign the CLA. See the comment from CLAassistant at the top.
If you have any issues, the other developers of the team can help you with that since they just recently also did this.