add Alps SKRTLAE010 horizontal push button

[hvraven]

This adds a horizontal SMT push button from Alps SKRTAE010. If this footprint is fine I would create the SKRTB variant as well which lacks the guidance holes. Designed to be used with the standard SW_Push symbol (however a SW_Push_MP might be nice to have).

I placed the center of the symbol in between the guidance holes, thats how I read the guidance lines in the drawing. I also used roundrects instead of square rectangles, I hope thats ok.

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[poeschlr]

please inlcude -MP in the name (after 1P1T) I did not review this any further

[cpresser]

• The center location is okay, its in the middle of the guide bosses.
• please add the keepout area as shown here:
  
• Body size is off by 0.01mm
• Then Pin1 marker seems wrong. There are two Pin 1, why did you choose the left one? This also raises the question if we need a Pin1 marker at all. If yes, it should also be on F.Fab. @poeschlr Any thoughts on this?

[hvraven]

Fixed the body size and added the keepout as shown below. Also dropped the pin 1 indicator. I added it in the beginning due to the labeling of the original datasheet. Then I did not delete it at the point where I realised that the pads on the side are connected to each other.

[cpresser]

Thanks!