[libadwaita] (6 commits) Non-fast-forward update to branch wip/exalm/style

[Adrien Plazas <aplazas src gnome org>]

The branch 'wip/exalm/style' was changed in a way that was not a fast-forward update.
NOTE: This may cause problems for people pulling from the branch. For more information,
please see:

 https://wiki.gnome.org/Git/Help/NonFastForward

Commits removed from the branch:

  8e01cc3... stylesheet: Round window corners
  7cc592e... stylesheet: Drop AdwWindow styles
  c800753... window-mixin: Drop the outline node
  cbb738f... window-mixin: Drop the unified style class
  cecd72b... window: Drop css node docs

Commits added to the branch:

  367c8c7... readme: Remove outdated build instructions (*)
  acb6be8... stylesheet: Round window corners
  838d242... stylesheet: Drop AdwWindow styles
  4afb1e1... window-mixin: Drop the outline node
  500a280... window-mixin: Drop the unified style class
  3df37b8... window: Drop css node docs

(*) This commit already existed in another branch; no separate mail sent