Escape spaces in file paths

[MarkMarzeotti]

Description

I came across an issue trying to commit for the first time at contributor day. Further up in my file tree I have a folder name with a space in it. npm install seemed to run fine, but when I tried to commit, the docs:build process was not able to run as it could not find the proper file path. Where the file path is created, this PR replaces the space with an escaped space.

CC: @aduth - thanks for your help with this!

How has this been tested?

Gutenberg plugin cloned and installed with a space in the path prior to the WordPress instance. My file path was /Users/mmarzeotti/Local Sites/contribute/app/public/wp-content/plugins/gutenberg/docs/tool/update-data.js for reference. Run npm run docs:build and it will be unable to find the files necessary to run. When spaces are escaped, the command runs as it should.

Types of changes

The same change (replace space with escaped space) is made in two places referencing docgen.

Checklist:

• My code is tested.
• My code follows the WordPress code style.
• My code follows the accessibility standards.
• My code has proper inline documentation.
• I've included developer documentation if appropriate.

[oandregal]

Hey @MarkMarzeotti thanks for the contribution! I'm sorry it took me so long to review (I was AFK).

I confirm I could repro the bug and this fixes it. Let's merge this in!