[MetaROR] Ch8 Communicating and Publishing — author revisions

[LukasWallrich]

Author revisions for Chapter 8 (Communicating and Publishing) from the MetaROR reviews (R1).

• Separate traditional publishing from other forms of communication. (R1) (in Separate publishing from other communication (Ch8, #21) #36)
• Mention that researchers can do either or both. (R1) (in Separate publishing from other communication (Ch8, #21) #36)

Handled in other issues:

• Move Chapter 8 content into Chapters 5 and 6 (new Sections 5.8 and 6.7; long table to an Appendix) → Structural reorganisation & scope