Add notes to API reference and tutorial section about mesh face vertices ordering convention

[yck011522]

Feature Request

As a [user], I want [to easily find out whether compas uses/ assumes mesh vertices ordering to be CW or CCW] so that it is explicitly spelled out and kept consistent.

Details

I think compas is using right-hand-rule for mesh face normal calculation. (I maybe wrong) I think this is not mentioned explicitly or at least not in the first 3 pages that I looked. In CG community I think CW / Right Hand Rule is often used, but it is not necessary true with all CAD platforms.

The only mention about normal and direction is the following sentence:

The ordering of the vertices determines the direction of its normal.

Doc pages I believe should add an explicit mention of the CW vs CCW convention: https://compas.dev/compas/latest/tutorial/meshes.html#data-structure-1 https://compas.dev/compas/latest/api/generated/compas.datastructures.Mesh.normal.html https://compas.dev/compas/latest/api/generated/compas.datastructures.Mesh.face_normal.html https://compas.dev/compas/latest/api/generated/compas.geometry.normal_triangle.html https://compas.dev/compas/latest/api/generated/compas.geometry.normal_polygon.html