FIxed broken link

Package manager link was pointing back to version control page insead of tools
removed hardcoded link added {{ HOME_PATH }}
Merge pull request #49 from thinkstylestudio/patch-1

FIxed broken link
Hotfix for f3d4f9005b since HOME_PATH is not working inside included file.
Merge pull request #51 from 10up/hotfix/fix-package-link

Hotfix for f3d4f9005b since HOME_PATH is not working
Code Style / Documentation Section Addition

Revised the example code snippet per @Rachelbacker's feedback that I was incorrectly speaking about protected meta soley for the purpose of hiding it from the Custom Fields meta box.

The new language speaks more to public vs protected meta and explains the difference.
Code Style / Documentation Section Addition

Modified the example function name so it better matches what the function actually does (per @Rachelbacker's feedback)
Code Style / Documentation Section Addition

Flushed out the example code docblock alignment
Code Style / Documentation Section Addition

Corrected a minor spacing issue per WP Coding Standards
Code Style / Documentation Section Addition

Relocated the add_filter hook above the example function to present better context.
Merge branch 'gh-pages' of github.com:10up/Engineering-Best-Practices into gh-pages
Merge branch 'gh-pages' into feature/documentation-section