Comments on new partition

[adrianVmariano]

• hide ptn_seg and move docs to partition_path
• Default length of segments seems questionable. Require a seglen= parameter to partition_path to specify that default (without which no default exists) or just require the value to be specified every time.
• Does it make sense to separate length so it's not in a string?
• The flat segment type is handled inconsistently with the rest. It does not have a name or a default length and has a number as a separate (well only) value in the list. This was confusing when I was reading examples without having studied the full docs. I think "flat 40" instead of 40 would be more consistent and cleaner, and would make the way the specifications work less confusing.
• Manual section for modifiers in ptn_seg should be written without the explicit shapes. When you write "sawtooth xflip" in the list, for example, I initially thought this was only a feature for sawtooth and not something generic. It should be "<shape> xflip" if you write it out. But actually, since (at present, they are all just text at the end you could just say that and then list them
• Should length modifiers (or modifiers in general) be separate strings? For lengths, in particular, that eases programmatic control of the lengths.
• Docs say things like "pinch:15". Do other numbers work? Negative numbers? Numbers over 100? Docs should say "pinch:" and explain legal range of val and behaviors across that range if notable.
• You could allow pinching by angle and have a remark that "don't pinch too much or the pattern will cross itself and become invalid". This could eliminate the need for finger and comb, as they could be obtained from square. It would also in theory eliminate the need for dovetail, though I think having that as a named thing makes sense. If you assume you know the pattern's dimension based on the specified length/width you can actually error check this to know the valid angle range.
• Noting issue with defaults: the default seems to be 25x25 but you can't even remember this, as one of the examples claims it's 20x20. Defaults that aren't somehow natural and obvious (guessable) are highly questionable. If you're giving a default, how will the user remember the default? Why is it natural? Why is this the choice users will want a lot of the time?
• If there's a default width in any way it should be possible to scale the height of a shape without changing it's width, which I didn't see.
• If you keep comb and finger you need to document their angles. Actually should doc dovetail angle as well.
• partition_path 2d examples are hard to see (line width too small)