doc: add commit formats for release blog posts

Created by: ghost

Checklist

• make -j4 test (UNIX), or vcbuild test nosign (Windows) passes
• tests and/or benchmarks are included
• documentation is changed or added
• commit message follows commit guidelines

Affected core subsystem(s)

doc

Description of change

this commit enhances the guidelines to creating a release blog post, specifically by adding a commit format that must be adhered to when creating a pull request on the website repository

refs: #8629 (closed)

/cc @TheAlphaNerd