require diagrams-lib >= 1.0.1 (for Hashable SizeSpec2D instance)

(cherry picked from commit 3a6b32ff21d639b714a60af694222a6723f3878d)
Bump version to 1.0.1.2
Release notes for 1.0.1.2

(cherry picked from commit 8bae3ec876c6c6220f57eb2374bccd87d2c418a2)