A way to define an articles "Related articles"

Welcome to Freshworks Community :)

I understand you wish to have control over the related articles that are displayed to the customer on your frontend portal(within the knowledge base). Though it is not possible to completely control this feature. Here’s what you can do - You could enable auto-suggestion of solution articles under Admin--> Channels --> Portals--> Settings and turn on the option to "Auto-Suggest Solutions while creating a new Ticket". Once this is done, the solution articles that are visible to the customers would be auto-suggested based on the Subject or Description entered by the customer while creating the ticket.

Besides that, you can use the interlinking articles capability to directly search for articles that can be linked to the content you are working on, without leaving the knowledge base text editor. To make use of this, highlight the portion of the content you would like to hyperlink and click on icon on the text editor. In the window that pops up, click on the Solution article tab. You will find that the Suggested article section displays all articles relevant to the content that you hyperlinked and you can fine-tune the results further by using the search bar. 

However, I do understand your point, We currently have moved the Ideas as a separate category in our Community. Access the Ideas forum and navigate to the section you want to submit an idea and suggest developments and also dive deep into the intellections of our Freshdesk community.

Cheers!