Updating the link to Assemblyline

[gdesmar]

Describe the change
The home page for the Assemblyline project has migrated from bitbucket to github. The link can be updated to reflect this change.

Describe testing procedures
No tests were ran but the markdown files should hopefully still render correctly.

Sample output
N/A.

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of and tested my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings