Rewrite contributing.md

[kellertuer]

Resolves #750.

@Affie can you take a look whether this is clearer now? I especially added an overview of files to consider when contributing.
Another Idea I can do, is to give a super short summary of what to do and which files to consider in the beginning of https://juliamanifolds.github.io/ManifoldsBase.jl/stable/tutorials/implement-a-manifold/, but that is something for another PR in that repository.

This also initialises vale.sh as a linter for the text to improve style and easier find bugs, since vale also highlights hints and errors in VS code when using their plugin. Vale is not perfect but maybe a good guide.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 96.39%. Comparing base (b3c0fa4) to head (9636973).
Report is 2 commits behind head on master.

Additional details and impacted files

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  Coverage   96.39%   96.39%           
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  Files         123      123           
  Lines       11441    11441           
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  Hits        11028    11028           
  Misses        413      413           

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[Affie]

Hi, yes the overview with the links will help a lot. I'm guessing the group "how to" will go into "LieGroups.jl". Perhaps when that is done, I should try to contribute the SpecialGalileanGroup we have here (if you want it): https://github.com/JuliaRobotics/RoME.jl/blob/master/src/factors/Inertial/IMUDeltaFactor.jl
I can follow the guide and let you know where I get stuck.

[kellertuer]

Nice!

Yes I plan to write a “How to Lie Group” once we have at least group operations fixed in LieGroups.jl, which should not take so long I hope – the first Lie group is nearly done. I want to do a second to be safe, and use that to write a tutorial.

But sure, new Lie groups are then super welcome over there!