default branch name not inclusive

#### Description of problem:

The default branch is currently "master" which is not inclusive with a majority of the public internet switching the default branch name to "main". Given the diversity within the security community it would be a good idea to make this change.

#### SCAP Security Guide Version:

Content 0.1.74

#### Operating System Version:

Not Applicable

#### Steps to Reproduce:

1. Clone repository
2. Create feature branch
3. Create pull request against default branch

#### Actual Results:

https://github.com/ComplianceAsCode/content/tree/master

#### Expected Results:

https://github.com/ComplianceAsCode/content/tree/main

#### Additional Information/Debugging Steps:

* https://sfconservancy.org/news/2020/jun/23/gitbranchname/
* https://about.gitlab.com/blog/2021/03/10/new-git-default-branch-name/
* https://github.com/github/renaming