"Manually Installing Shape-Sketch" section in README.md is for Git Manager

[jojomoore2007]

The 2nd bullet point in the README's "Manually Installing Shape-Sketch" section tells you to download and extract the latest release of "Git Manager" into the sketchbook/tools/ folder, linking to Git Manager's latest release page, when it should be referencing Shape-Sketch.

What the text says:

Download the latest release (GitManager.zip) and extract it into the "tools" folder. Ensure that in the tools folder, GitManager folder has src, tools, etc. within it, and not another sub-folder named GitManager.

What it should really say:

Download the latest release (ShapeSketch.zip) and extract it into the "tools" folder. Ensure that in the tools folder, ShapeSketch folder has src, tools, etc. within it, and not another sub-folder named ShapeSketch.

Here's the markdown for that fix:

Download the latest release ([ShapeSketch.zip](https://github.com/joelmoniz/Shape-Sketch/releases/tag/latest)) and extract it into the "tools" folder. Ensure that in the tools folder, ShapeSketch folder has src, tools, etc. within it, and not another sub-folder named ShapeSketch.