[Add]: How to override BP Styles

[imath]

What needs to be done?

Reviewing #116 I realized we need to add a specific page to explain how you can replace the BuddyPress styles used in Template packs

Used > Advanced > Customizing Styles

Handbook to add the page in

buddypress/docs/user

Tasks to accomplish

• This task has been added to the "Todo" panel of the Documentation project.
• A PR has been submitted to the BuddyPress GH repository, it has been linked to this issue/task & the task was moved to the "In progress" panel of the Documentation project.
• The PR has been converted to a SVN patch and committed to the BuddyPress SVN repository & the task was moved to the "Done" panel of the Documentation project.