feat: add material design to admin

[rmagon]

@sunk0 you can either use this branch or merge it into your own and delete this PR

[evereq]

Hm, I think we should be just doing exactly what is done in akveo/ngx-admin@master...feat/material-theme. I.e. why we reinvent the wheel?

[rmagon]

Oh I will check that, this is the same as what's already done in this project for shop-web so I thought for consistency we should do the same?

[evereq]

@rmagon haha, I think best to use what ngx-admin did :) Our shop-web based on Angular boilerplate, not on ngx-admin (so we keep it less overloaded with features)

[evereq]

@rmagon @sunk0 also this is the lowest priority at the moment :)

[rmagon]

@evereq Haha okay sure. @sunk0 You can keep the checkbox only for now then 😄

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