Merge pull request gTile#412 from gTile/gnome48

Gnome 48 support (and bump bump extension version to 64)

Update CHANGELOG.md

Merge pull request gTile#406 from gTile/autotile-ratio

Autotile ratio

Merge pull request gTile#399 from gTile/feature/gnome47

Gnome 47 support

Merge pull request gTile#355 from gTile/testing

Maintenance release (add testing, fix typo) & add new "snap-to-grid" setting.

Gnome 46 compatibility (release V59).

Merge pull request gTile#371 from gTile/ui-placement

Position gTile overlay in the center of the focused window

Merge pull request gTile#370 from gTile/keybindings

Exhaustive Keybindings for Interactive Window Resizing

Prepare release V56.

Merge pull request gTile#356 from gTile/compat

Compatibility for gnome.extensions.org