Drawn diagrams to help people understand measurements

[terriko]

It would be nice to have some creative commons licensed artwork for explaining certain types of measurement in our documentation and in interactive patterns. Here's an example of a non-creative-commons (but free) pattern helper blog post that includes extensive diagrams:

https://blog.tincanknits.com/2013/10/25/lets-knit-a-sweater/

The idea here is to have some artwork as part of pyknit that people could re-use without copyright concerns, so finding something free on the internet that has an explicit permissive license would be ok, but including diagrams from free (but not permissively licensed) patterns would not. It's probably easiest to draw some new stuff since knitting diagrams are not typically creative commons licensed.

Some diagrams we could use right now:

• How to measure gauge.
• sweater sleeve measurements