Rewrite description for URL alias on node/add/*

Problem/Motivation

(Why the issue was filed, steps to reproduce the problem, etc.)

Proposed resolution

(Description of the proposed solution, the rationale behind it, and workarounds for people who cannot use the patch.)

Remaining tasks

(reviews needed, tests to be written or run, documentation to be written, etc.)

User interface changes

(New or changed features/functionality in the user interface, modules added or removed, changes to URL paths, changes to user interface text.)

API changes

(API changes/additions that would affect module, install profile, and theme developers, including examples of before/after code if appropriate.)

Data model changes

(Database or configuration data changes that would make stored data on an existing site incompatible with the site's updated codebase, including changes to hook_schema(), configuration schema or keys, or the expected format of stored data, etc.)

Original report by Jayly

Note: This issue is being posted here as an exercise by a participant in the http://drupalladder.org ladder for contributing to core. Please don't do anything with this post. The real issue has already been resolved in Drupal 8. If you would like to try this exercise yourself, visit http://drupalladder.org and click on Drupal Ladder

Current:
Optionally specify an alternative URL by which this content can be accessed. For example, type "about" when writing an about page. Use a relative path and don't add a trailing slash or the URL alias won't work.

Proposed:
The alternative URL for this content. For example, type "about" when creating an about page. Use a relative path without a trailing slash