Create documentation page for setting up l10n_server on Drupal 7 locally

Problem/Motivation

We need to create a documentation page under the contributed module documentation for Localization Server (l10n_server) explaining how to install and set up the Drupal 7 version locally for testing purposes.

Steps to reproduce

Proposed resolution

Create a new documentation page under:
https://www.drupal.org/docs/extending-drupal/contributed-modules/contrib...

Remaining tasks

User interface changes

API changes

Data model changes