Some TypeScript declarations are wrong

Some TS declarations don't match the documentation

Full list (maybe I skipped something):
quat2.length quat2.squaredLength quat2.setReal quat2.dot

I think that's an unfortunate consequence of how the Typescript declarations have been written. A dual quaternion's length is the same as the length of the real part (the first 4 elements)

gl-matrix/src/quat2.js

Line 784 in 0b4bfe9

export const squaredLength = quat.squaredLength;

And the length of a quaternion is the same as the length of a vector

gl-matrix/src/quat.js

Line 648 in 0b4bfe9

export const squaredLength = vec4.squaredLength;

This is probably worth fixing