[css-transforms-2] Order of sections in Transforms 2 is wrong

[birtles]

CSS Transforms 2 has the following outline:

11. SVG and 3D transform functions
12. The Transform Functions
    12.1 3D Transform Functions
    12.2 Transform function primitives and derivatives
    12.3 Interpolation of 3D matrices
    12.3.1 Decomposing a 3D matrix
    12.3.2 Interpolation of decomposed 3D matrix values
    12.3.3 Recomposing to a 3D matrix
13. Interpolation of Matrices
    13.1 Neutral element for addition
14. Interpolation of primitives and derived transform functions
15. Addition and accumulation of transform lists
16. Mathematical Description of Transform Functions

However, it seems like all the talk about interpolating 3D matrices really belongs under section 13 (and the neutral element for addition part, if needed at all, should not go under 15).

Looking at the changeset that introduced this structure: 9ff1588 it seems to differ from CSS Transforms 1 where the content was imported from. In CSS Transforms 1 the "Interpolation of 3D matrices" was a subsection of "Interpolation of Matrices".