Create baack.md for Baack headless content management system. - #1080

Changed pages include:

• index.html - view
• _getting-started/index.html - view
• _styleguide/index.html - view
• code-of-conduct/index.html - view
• community/index.html - view
• generators/index.html - view
• glossary/index.html - view
• headless-cms/index.html - view
• logos/index.html - view
• resources/index.html - view

There are more changes not included in the list