Add related tools to articles

[GraemeFulton]

right now there's a relation from articles to tools but it's for interviews

interviews has many tools, tools many interviews

need another for posts to tools that don't have to be interviews

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option 1:

• change interviews to posts
• add query for interviews that filters posts with tag interview

option 2:

• add an extra relation (probs less work but seems like it can be more confusing)