add a story to the docs - custom header menu

[Shlomi Assaf]

This story should demonstrate how to use the column header component rendering extension to render a row for filtering the column (e.g. MatSort) + a menu context that will open with stuff inside (hide, sort etc...)

This should also demo how to create a value filter that can change base on definitions.
For example, a numeric cell that switch from range (between), equals, LT, GT, in etc..

If possible, the demo should include a use of the rendering extension for header as described above and also a dedicated row, so users can see the 2 ways it can be done.

Inspiration:

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The core package @pebula/ngrid does not come with these kind of components, they are not part of the core and will never be so we need to show how to create them until we have a package that does that magic.

In the process we might run into issues that will require fixes/features etc, so it's a pending to the 1.0.0 milestone.