Methodology guidance

**Is your feature request related to a problem? Please describe.**

Some extra detail to the methodology section would be helpful around whether they're required, different ways of uploading them and sign off processes.

**Describe the solution you'd like**
Some extra guidance around methodologies on EES would be helpful. This includes:

- [ ] guidance around if methodologies are necessary to publish on EES or not and why. I
- [ ] have examples of when it's ok to have a methodology in the publication release (when the release is short for example) and when to have it in a separate section.
- [ ] have guidance around methodology sign off

Start by locating the methodology section in the EES guidance and read the surrounding publication-release guidance. Done means documenting when methodologies are required and why, how they may be uploaded or placed in a release or separate section, and the methodology sign-off process.

Written by the indexing model from the issue text.