Fix documentation for "Error: Closure not found"

After installing the way the wiki explained, and opening tests/horizontal_playground.html, I got an alert saying:

Error: Closure not found.  Read this:
developers.google.com/blockly/hacking/closure

It looks like you need to have closure-library installed in the lower directory.

calcdeps = import_path(os.path.join(
  os.path.pardir, "closure-library", "closure", "bin", "calcdeps.py"))

That, honestly, feels like bad design (i.e. I keep my GitHub projects in one directory and other random clones in another, so I don’t really want closure-library, which I don’t contribute to, in my I-contribute directory).

After getting closure-library installed at scratch-blocks/.., running build.py again, and opening the example/test file again, it worked.

[towerofnix]

Assuming you’ve used a terminal before…

cd <where you put your github prjoects>
git clone https://github.com/google/closure-library.git
git clone https://github.com/LLK/scratch-blocks.git
cd scratch-blocks
python build.py
# Now you can experiment by opening up
# tests/horizontal_playground.html :)

Of course, you’ll need git and python installed.

[towerofnix]

Replace npm i closure-library with git clone https://github.com/google/closure-library.git.