Create a multisite htaccess file when enabled

[ampersarnie]

Description

Fixes #52 - .htaccess files require different configuration depending on whether multisite is enabled and based on which type - subfolder or subdomain. Previously only a single site .htaccess file was created no matter the config. To correct this I've introduced two multisite .htaccess templates that will be used when their type is selected.

Change Log

• Added subdomain .htaccess
• Added subfolder htaccess
• Change dockerfile tempalte to use htaccess name variable
• Change config creation to pass htaccess file name to template

Types of changes (if applicable):

• [x] Bug fix (non-breaking change which fixes an issue).
• [ ] New feature (non-breaking change which adds functionality).
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected).

Checklist (if applicable):

• [x] Meets provided linting standards.