Prepare for 1.28 release (NanoComp#2708)

* prepare for 1.28 release

* Update NEWS.md

* Revert "Update NEWS.md"

This reverts commit 9f0cc7b.

* news for 2631

* news links

* news tweak

* news tweak: mention label_geometry=True

* shared lib major version doesn't change since header file is unchanged

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Co-authored-by: Steven G. Johnson <[email protected]>

NEWS links

rm doc dir from release tarball

Prepare for 1.25 release (NanoComp#2311)

* prepare for 1.25 release

* add bug fix to NEWS.md and refresh documentation from docstrings

* link fixes

Co-authored-by: Steven G. Johnson <[email protected]>

prepare for 1.24 release (NanoComp#2143)

release date

NEWS links

Prepare for 1.21 release (NanoComp#1786)

Prepare for 1.20 release (NanoComp#1723)

* Prepare for 1.20 release

* remove nightly built Conda package from the installation page

* update description for subpixel smoothing of MaterialGrid

* bump 1.20.0 date, update links

* whoops

* version bump

Co-authored-by: Steven G. Johnson <[email protected]>

version bump