Update v0.8.1

v0.8 - The multiple project & Web update!

Fixes critical bug with saving projects that contained linked cels

It used to save the linked cel array which contained the canvas nodes into the .pxo. This, however, does not make sense, because the canvas nodes are being recreated when a .pxo is loaded. Therefore, they are different nodes than they used to be.

Now, an array containing the frame numbers which have cels linked for each frame is being saved and loaded into the pxo.

Update README.md

v0.6.1 release

v0.6 - Palettes, random brushes, multiple themes, image menu and many…

… more!

v0.5 - The UI update

This commit fixes a bug with graphics tablets not being able to use undo and redo. v0.5 will be built from this commit.

v0.4 - Undo/Redo, mirrored drawing, lighten/darken tool and more!

In this commit:
- Added notification labels that appear when the user does an action (for undoing, redoing and saving)
- Fixed symmetry with custom brushes.
- In Main.gd, current_save_path and current_export_path get cleared when the user creates a new drawing or opens one.

v0.4 of Pixelorama is out! Check https://functionoverload590613498.wordpress.com/2019/11/13/pixelorama-v0-4-is-out/ for the full changelog.

v0.3 - Custom brushes, rectangle selection and .pxo!

v0.3 of Pixelorama is out! Check https://functionoverload590613498.wordpress.com/2019/10/22/pixelorama-v0-3-is-out/ for the full changelog.

Update README.md